ID NO.:2015A3PS294H

GROUP NO. :25

LECTURE SECTION :2

TOPIC :Retinal Phototherapy
   The rapid advancement of MASER(Microwave Amplification by Stimulated Emission of Radiation) and LASER(Light Amplification by Stimulated Emission of Radiation) has provided medical science with a therapeutic coherent light source.Energy from low-power laser(4000 A-9000 A) is focused on the retina of the eye.A solid state ruby laser(with a Xenon flash tube) may be used to produce good chorioretinal adhesion with minimum structural damages to the tissues. Wave fronts travelling perpendicular to the end mirrors are amplified by being reflected back and forth throughout the crystal.The laser beam is focused on the exact spot on the retina.                      

 Preliminary clinical experiments which were carried out on rabbits are described and results are compared with those on human beings.The differences between laser lesions,diathermy lesions and Xenon arc coagulator are discussed.The use of various laser's in industry is referred and possible hazards as laser's become widespread are discussed. With  higher laser energies molecular tissue  disruption can be explosive.   Laser technology can seal a hole or a tear in the retina with less disturbance to its function.Furthermore,laser eye surgery has greatly reduced the need for spectacles and provided an effective solution for cataract.It is thus a highly effective therapeutic light source.                        JOURNAL: http://www.jstor.org/stable/25405073?

LECTURE SECTION:  2

TOPIC: Application of LASER in
nuclear industry

Light Amplification by Stimulated
Emission of Radiation (LASER) has its use in many fields of everyday life. The
applications of LASER in the nuclear industry is one of the important uses of
LASER in today's life.

Scientists have been studying how
energetic LASER beams can affect the nucleus of an atom upon the
forced interaction of LASER and a reactive nucleus. For
this, high intensity LASER beams are produced by Chirped Pulse
Amplification(CPA) which consists of successive stretching and compression
of duration of LASER pulse. When this high intensity LASER pulse is focussed
onto solid and gaseous targets, it has been observed that the electrons start
to vibrate with energy greater than their rest mass energy (0.511 Mev)  It
has been proposed that intense LASER light can produce huge number of
 oscillations in plasma. Plasma is  ionised gaseous matter containing
equal numbers of positive ions and free electrons. Similarly, high energy
protons can be produced but the processes involved are quite complex. Briefly,
it can be said that protons are accelerated by electric fields which are
produced due to ionisation of hydrogen atoms by other high energy electrons and
ions produced by LASER.

This production of accelerated
particles can induce nuclear processes and one of the primary uses is
obtaining energy from such processes. Photochemical emission  is also
another important outcome of these nuclear processes.

Whenever these accelerated
particles strike a nucleus, the nucleus gets excited to a higher level of energy.
When it subsequently de-excites, it emits gamma rays, in the form of massless
photons. These gamma rays possess huge amount of energy. The spectra of nuclear
emission can be effectively studied to get more insight into LASER induced
nuclear emission.

LASER has also been used
to produce neutrons. This has been possible by the
fusion of deuterium in LASER-produced plasma. With development of
Titanium-sapphire laser technology, practical applications of LASER-generated
neutrons have become possible. Monoenergetic neutrons can be used to study
damage of materials and their healing time as neutrons pass through them.
Other uses are in study of biological materials and other phenomena at
sub-nanosecond time scales.

Future prospects of LASER in
nuclear industry are rich. It has been found that at very very  high
intensities, LASER can directly be used to excite nuclei. This can alter decay
lives of nuclei which can be used to address nuclear waste issues. Research is
going on in the application of high intensity LASER in the field of
astrophysics. 

Lecture Section-2

Group No.25

TOPIC : HIGH-ENERGY LASER WEAPONS

The laser is perhaps the most important optical invention in the last several decades. Since its invention in the early 1960s, the laser has proved to be an extremely useful device not only for the scientific and commercial communities, but also for the military and Air Force. At first, it was considered to be 'a solution without problem', because the technology appeared before the vision.

Today, laser is at the heart of an extensive array of various military applications. Numerous countries are now developing their own laser technologies for weapon applications. Since the early 1960s, lasers have demonstrated the capability to produce sufficient energy to merit serious considerations, even by most ardent skeptics, as a potential weapon against ballistic missile threat.

The chosen article discusses some of the pioneering approaches of United States to develop laser weaponry system as well as some of the ups and downs faced during its development, for example, its expensiveness and the unprecedented secrecy in which it was kept initially. This article discusses the limitations faced and their overcoming as well as future aspects and profound influence of laser weaponry on arms race.

Link to the journal : http://www.jstor.org/stable/3961467

Do you think the future prospect of LASER weapons

Has extensive research been done or is it still a relatively new topic?

Now it has achieved a much wider scope.

Its ability to destroy a missile at the speed of light makes it an extremely attractive weapon against ballistic missiles.

Military scientists have been pushing laser technology to achieve greater laser power, better optics, and improved target acquisition, tracking and pointing technologies.

Although, Albert Einstein developed theoretical foundation of laser in 1917

High power LASER, because of its low wavelength, can be easily absorbed by metals and their alloys. Precise positioning of the LASER beam is ensured by a LASER fibre delivery system. The beam is directed longitudinally along the fibre. After a series of total internal reflections, the LASER beam strikes the metals to be welded together. The fibre is made of a suitable material so that the LASER beam does not attenuate(weakens) as it passes through the beam. Also a convex lens is used to focus the LASER beam at a particular point. These images will make you understand better.

However application of higher dosages causes an immediate explosive disruption of the tissues.An increasing number of people are employed in using such devices and are consequently exposed to this industrial hazard.

(My question is quite specific since I know quite about nuclear industry)

Particles and Astrophysics,  cutting and welding, weaponry, tests of quantum electrodynamics, huge magnetic field generation and the production of Hawking radiation

A:1.One line produced a new generation of cutting and welding

2.Second line was trying to explode tiny hydrogen pallets to produce fusion energy.

3.The third line of research was weapon's development

ANS : The laser beams travelling through atmosphere face a variety of disturbances like absorption by molecules, scattering by aerosol particles, diffraction by aerosol particles and "thermal blooming",that is, defocussing of beam due to heating of air in its path.

To overcome these problems, COAT (Coherent Optical Adaptive Technique) was established to reform and reshape beams so that interference can be minimized.

I got a suitable journal on my topic at Jstor. For further reference I read few other journals on the net as well as in the library.I took relevant information from wikipedia and Google Scholar's.To have a better understanding on my topic I watched some You Tube videos and went through self-explanatory pics on Google.

For collecting the information related to uses of laser in weaponry (especially in the military), I referred to two or three journals apart from my chosen journal, which consisted more information regarding the current status of laser weaponry in military, space-based and ground-based architecture ( including comparision with "anti-ballistic missiles" as well )

And as you must have guessed, I have gone through wikipedia as well, searched on youtube (however couldn't get much information out of it as it was beyond my level).

I also went through some power-point presentations available in the internet based on my topic, containing a lot of pictures and information, aiding me in getting a much better hang of my topic.

 Although I chose a particular journal of JSTOR as my document, I did not confine myself to this journal only. I went through many other journals present on JSTOR, Project MUSE, Elsevier and searched the internet itself to get more information on my topic. I realised that a lot of research has already been done in my topic.  I viewed images on Google, watched videos on YouTube to gain more insight into the practical aspects of my topic. I listened to a lecture given by a professor on the topic of acceleration of particles by high-intensity LASER on YouTube. These all helped me a lot in understanding more about my main topic LASER- nucleus interaction.

K.W.D Ledingham

P. McKenna

R.P. Singhal

VULCAN at the Rutherford Appleton Laboratory in Oxfordshire, U.K.

NOVA at Lawrence Livermore National Laboratories in California

It has been proposed that when high-energy LASER strikes the target surface, a burst of energetic electrons and ions are produced. When the electrons go through the thin sheet, they ionise the hydrogen and other atoms. Because of the presence o positive ions and negative electron sheets, huge electric fields are generated which ultimately accelerate the protons.

You Tube links

1.https://www.youtube.com/watch?v=KDgZZhARLsQ

2.https://www.youtube.com/watch?v=EmtYivWUH7Itt

3.https://www.youtube.com/watch?v=UezYWOqPQ_Q

4.https://www.youtube.com/watch?v=lXzqwzQo0Oc

5https://www.youtube.com/watch?v=gQ_qMuP5itw

Online sites

1. www.webmd.com/eye-health/lasik-laser-eye-surgery

2.www.medicinenet.com › ... › eyesight az list › lasik eye surgery index

3. www.lasikcomplications.com

4.www.lasik.com/articles/laser-eye-surgery-what-is-it/

5. www.surveyophthalmol.com

Journals

2. http://www.jstor.org/stable/10.2307/23049573?

Book

1.LASIK: The Evolution of Refractive Surgery

Publisher: SLACK Incorporated

Author: Dr. Lucio Buratto

Edition:1

Year of Publication:2011

city o

My chosen article on 'High-energy laser weapons'

WEBSITE LINKS :

1. http://science.howstuffworks.com/laser-weapon.htm 2. http://indiandefence.com/threads/laser-basics-and-military-applications.630/

YOUTUBE LINKS: 1. https://m.youtube.com/watch?v=OmoldX1wKYQ 2. https://m.youtube.com/watch?v=xaCAP5ZJ0Gw 3. https://m.youtube.com/watch?v=5wTiBRwuTS4 4. https://m.youtube.com/watch?v=5wTiBRwuTS4

There are three more documents as well which helped me more than my original chosen journal:

Source document no. 1

1. LASER aiding in the process of nuclear fusion: 

https://www.youtube.com/watch?v=RMfCisKMnWY

2.More on cutting and welding with LASER:

https://dspace.lib.cranfield.ac.uk

3.Demonstration of cutting with the help of LASER:

https://www.youtube.com/watch?v=pMSyGOoesfM

4.Fusion Energy Breakthrough:

http://www.scientificamerican.com/article/high-powered-lasers-deliver-fusion-energy-breakthrough/

5. Lecture on particle acceleration by high intensity LASER:

https://www.youtube.com/watch?v=r8VNTspuxVA

6. More on LASER in nuclear industry

Q.1 Which is the most efficient technique for LASER surgery ?

a)Photorefractive keratectomy

b)LASIK

C)Intraocular lens

d)Refractive lens exchange

Q.2 Is LASER eye surgery risk-free in terms of the eye tissues?

a)Yes

b)No

Q.3 What is the most important factor for you to get a LASER eye surgery?

a)Price

b)Financing

c)Convenience

d)Quality and Reputation

Q.4 Are there any long-term side effects involved in LASER eye surgery?

a)yes

b)no

Q.5 What is your perception of LASER eye surgery?

a)too expensive

b)risky

c)safe and effective

d)affordable and convenient

VASHISTHA - QUESTIONNAIRE

Q.1 In which field do you think the progress OF LASER will be more rapid in new future?

a) Weapon technology

b) Nuclear industry

c) Cutting and welding

d) Cardiovascular surgery

e) Eye treatment

Q.2 Do you think the expensiveness of LASER will hinder it's progress in weapon technology?

a) Yes

b) No

Q.3 Which country, according to your knowledge, has made the best use of laser technology in weaponry till now?

a) USA

b) USSR

c) India

d) China

e) Japan

Q.4 According to you, which factor makes LASER the best missile destroyer?

a) it's precision and accuracy

b) lightening speed

c) both

d) none

Q.5 In which field in weaponry is LASER used most till now?

a) Acquisition

b) Fire control

c) Defense against missiles

d) Tracking and pointing

1.Ophthalmology-branch of medicine that deals with the eye and its diseases.

2.therapeutic-healing or restorative .

3.Optical coupling: coupling between two circuits by a light beam or light pipe having transducers at opp-osite ends, to isolate the circuits electrically.

4. Solid-state laser  : a laser that uses a gain medium that is a solid

5.cumbersome-large or heavy.

6.fundus : part of a concavity in any organ, which is at the far end from its opening.

7.flash tube: also called a flashlamp, is an electric arc lamp designed to produce extremely intense, incoherent, full-spectrum white light for very short durations.

8.volatilisation: process whereby a dissolved sample is vaporised

9:refractive error:an error in the focusing of light by the eye

10.dichroic mirror:very accurate colorfilter used to selectively pass light of a small range of colors while reflecting other colors. 

11.suture:a stitch or row of stitches holding together the edges of a wound or surgical incision.

12:lesion: abnormality in the tissue of an organism usually caused by disease or trauma

13:bulla:a large blister containing serous fluid. 14:histology:the study of the microscopic structure of tissues.

15: retrobulbar :situated or occurring behind the eyeball.

16:diathermy: a therapeutic treatment prescribed for joint conditions such as rheumatoid arthritis and osteoarthritis.

17:Catholysis:Electrolysis with a cathode needle.

18:prophylactic;preventive or precautionary.

19:vitreous:glassy appearance.

20:choroid:vascular layer of the eye, containing connective tissue, and lying between the retina and the sclera.

21:sclera:outer layer of the eye containing collagen and elastic fiber.

22:hyaloid:glassy,transparent

23:proliferate:multiply

24:plexiform:resembling a network

25:pyknosis: irreversible condensation of chromatin in the nucleus.

26:plaque:an ornamental tablet, typically of metal, porcelain, or wood.

1.BALLISTIC - Relating to the motion of objects moving under their own momentum and force of gravity. 

2.ANTIBALLISTIC MISSILE - A defensive missile designed to shoot down intercontinental ballistic missiles.

3.QUAGMIRE - A complicated, difficult or confused situation.

4.PEREMPTORY - Not allowing contradiction or refusal ; putting an end to all debate and actions.

5.THERMAL BLOOMING - A picturesque term for the defocusing of a beam that occurs as the air heats up along its path.

6.MAR - Destroy or injure severely ; blemish ; mutilate

7.DETENTE - The easing of tensions or strained relations (especially between two nations).

8.ENAMORED - Marked by foolish and unreasoning fondness, becharmed, bewitched.

Amplification: The act of enlarging or replicating in large number

Microns: One millionth of a metre.

Dispersive gratings:  Objects which disperse a beam of light (or other electromagnetic radiation) into its wavelengths to produce its spectrum

Wake of oscillations: Number of oscillations

Brehmsstrahlung radiation: Electromagnetic radiation produced when a charged particle is decelerated by another charged particle (Eg. An electron decelerated by a nucleus)

Burst of electrons: A huge number of electrons released abruptly

Radiopharmaceutical: A radioactive compound used in diagnosis or therapy.

Annihilation: Physics  The process when a particle and its antiparticle meet to produce a huge amount of energy (Eg. Electron and positron)

Bragg peak: It is a peak on the Bragg curve which plots the energy loss of ionising radiation as it travels through matter.

Transmutation: The conversion of one chemical species(usually isotope) into another.

Population inversion: This occurs, when more members of a system (consisting of electrons, protons etc.) are in excited states than in lower energy states.

So lasers, in weaponry, are currently used in:

1.Tracking

2.Target designation (acquisition)

3.Fire control

4.Pointing

5.Ranging

6.An alternative to radar

7.Blinding troops

8.Defensive countermeasures

9.Communication

10.Ground-based architecture

According toscientists are currently working on three futuristic applications of laser in military (though there are many) :

1.Directed Energy Weapon (DEW)

2. Space-based laser architecture

• angioplasty
• cancer diagnosis
• cancer treatment
• cosmetic dermatology such as scar revision, skin resurfacing, laser hair removal, tattoo removal
• dermatology- to treat melanoma
• lithotripsy-a treatment by which a kidney stone or other calculus is broken into small particles
• laser mammography-to diagnose and locate breast tumours
• medical imaging
• microscopy or spectroscopy
• ophthalmology (includes Lasik and EpiLasik
• optical coherence topography
• prostatectomy
• plastic surgery, in laser liposuction
• refractive and eye surgery(eg. cataract surgery)
• photocoagulation of the retina and to halt tacking of retinal tears.
• in dentistry for caries removal, endodontic/periodontic procedures, tooth whitening and oral surgery.
• skin health assessments.
• photobiomodulation-It is a light therapy using lasers or LEDs to improve tissue repair, reduce pain and inflammation wherever the beam is applied.
• Laser scalpel (General surgery, gynecological, urology, laparoscopic)

Among the mentioned futuristic applications, according to my knowledge and findings, both have equal chances of being developed and used in near future.

But if I am asked to chose one, I will go with Directed-energy weapons (DEW). Currently it is not used in military but is being considered for non-military use to protect Earth from asteroids.

In my opinion, DEW has greater scope in military and scientists are planning to use it as soon as possible (though the exact number of years is difficult to say, maybe within 5-10 years). It has lots of advantages over conventional weaponry:

1.DEWs can be made visible or invisible, since it can be used at discreet wavelenths.

2.Evading a DEW attack is nearly impossible, due to its high accuracy and lightening speed (lasers travel with speed of light).

3.Given a sufficient power source, it will have limitless ammunition.

4.It cannot be deflected or intercepted and it has no counterattack.

5.It is unaffected by physical factors like gravity or windspeed.

And there are lots more and I cannot jot down here each and everyone of them.

Scientists are really endeavoring to advance this technology since it has the power to revolutionise sonic weapons and particle-beam weapons. 

It is not quite feasible now, but it doesn't mean that it will not be for long because taking in consideration the current progress rate in laser technology and its usefulness in military, scientists, after overcoming some small problems and with some rectifications and new innovations, will make it feasible in years to come.

Space-based laser architecture also has sufficient scope but it will take more time and researches to develop.

Lasers have revolutionized sight correction procedures and now new techniques and products are about to advance the eye-care revolution.Laser sight correction surgery is one of the fastest improving fields in medicine.Anyone of a certain age who finds themselves donning bi-focals, or having to swap between glasses for mid-to-longer range vision and another pair for reading, may be able to get rid of them over the next few years.The future applications of LASER in eye surgery may be as follows:-

1.Pixel Optics digital eyewear may well replace traditional progressive lenses. Containing a layer of transparent liquid crystal, these new lenses electronically alter how the lenses refract light, meaning they will adapt from reading the paper to driving in 0.025 seconds

2.The ultra short beams of the femto-second LASER's are precise enough to avoid damaging healthy material and have been proven to offer a safer option to existing practices.LASER eye surgery pioneers say that these LASER's will make human eyesight upto five times better in the future.

3. Wave front technology-This gives measurement of the variable curvature of the cornea across its surface, to allow for both better contact lenses and more accurate laser surgery, as many possible aberrations particular to each individual eye can be corrected.

The future of lasers in eye surgery already promises to bring about a world in which no one needs eyeglasses or contact lenses. Reshaping the cornea with laser light is now a common medical procedure; but in only a few years doctors will be able to go further and completely reshape the human eye using laser beams. One beam will precisely measure the eye in three dimensions to pinpoint any problems and feed the information into a computer, which will figure out exactly how the eye should be reshaped. The doctor then will use a different beam to cut the eyeball at various strategic points and another beam to weld the incisions together. Eventually, the eyeball will be shaped correctly, and the person will be able to see with perfect twenty-twenty vision.

FEASIBLE SUGGESTION

Of the above mentioned applications of LASER's in eye surgery the most feasible one according to me is related to the wave front technology.One such system is the ORA system (Wavetec) which, using aberrometry, measures intraoperative refraction once a lens is removed and also when the lens is implanted. Toric alignment and optimisation can also be accomplished. The system has application in confirming appropriate lens power in those who have had previous laser eye surgery where lens calculation using conventional biometric methods can be quite challenging.

In future not only will the best refractive option be provided but also the type of lens best suited optically to the individual or perhaps a planned bespoke laser ablative procedure.The preoperative diagnostics will be integrated into the lasers used for laser refractive surgery or lasers used for cataract/refractive lens exchange and microscopes, and employed, for instance, to assist aligning toric lens orientation. Intraoperative diagnostics will confirm lens power and refractive outcome before completion of the surgical case.

Q1) In context of LASER technology, what is CPA?

a) Chirped Process Amplification

b) Coded Process Amplification

c) Chirped Pulse Amplification

d) Chirped Pulse Activation

Q2) What should be the intensity of LASER radiation that must be focussed onto solid and gas to produce electrons with energies greater then their rest mass?

Q3) Do you think the future of LASER in nuclear industry is bright?

a) Yes, of courses

b) Depends on many other factors

c) No

d)Cannot comment right now

Q4) What is the antiparticle of an electron?

a) Neutron

b)Positron

c)Muon

d)Gluon

Q5) Why are protons accelerated preferentially with respect to heavier ions by LASER?

a)Because of their high charge-to-mass ratio

b)Because they attract LASER

c)Because heavier ions repel LASER

c)No specific reason

Q6) Please point out how this technology might be misused in future and ways to prevent such misuse or mitigate the dangers:

Q7)How informative and useful have our padlet posts been?

a)Very Much

b)Much

c)So-so

d)Not at all informative or useful

Q8) Would you recommend our Padlet posts to anyone else?

a)Yes

b)No

Q9)Please tick your profession:

a)Teacher

b)Student

c)Scientist

d)Doctor

e)Other

Q10) Please provide suggestions to improve our Padlet posts:

Through my survey I wanted to know many things. Firstly, I wanted to know how much knowledge people already had about my topic. Then, I also took their opinions on certain crux issues and the prospect of  using LASER in nuclear industry to induce various nuclear processes in the future. Also, I aimed at knowing the profession of the people who all responded to my survey. My target audience includes people of any profession, provided they have ample interest in my topic : Application of LASER in nuclear industry. However, I also put many technical questions in my questionnaire to get the opinions of experts in my field so as  to know if indeed a lot of research has to be done in my topic or not. The target audience includes nuclear scientists who have profound knowledge and vast experience. The questionnaire also aims at capturing the interests of tech-oriented students. Engineers who can apply their knowledge of LASER in their respective fields are also part of target audience. I have even included teachers in my target audience so that they can increase their knowledge in this field.

My topic is: Application of LASER in nuclear industry. Here I propose some of the applications in which my topic can be put to use.

1.To obtain large amounts of nuclear energy: LASER can induce nuclear fission and fusion and hence lead to the release of a huge amount of energy. This energy can be harnessed to meet energy demands all over the world.

2. Use of LASER-produced plasma:

LASER-produced plasma acts as a wonderful source of X-Rays and it can be used in a wide range of fields.

3. Addressing the nuclear waste problems:

At very high intensities, LASER can directly excite the nuclei and hence can alter the half life and decay periods of these nuclei. This can lead to important applications in treating nuclear waste treatment.

4. Production of very very strong magnetic fields to initiate nuclear fusion:

High intensity LASER can excite the electrons of plasma to relativistic velocities. The interaction of LASER with plasma produces high current electron jets. The interaction of relativistic oscillation and high current jetting produces very strong magnetic fields. This can initiate nuclear fusion reaction.

5. LASER nuclear fusion jet engine:

In this technique, we bub perform the experiment in a cavity of an engine. A quantity of fuel is taken in a cavity and it is blasted with high intensity LASER. This makes it release a huge amount of energy which drives the walls of the engine forward. Also some of the energy heating up the wall is harvested to drive the LASERs

Amongst the suggestions put forward by me, I feel my application can be put to utmost use in treating nuclear wastes. It is because proper disposal of nuclear waste is the need of the hour. We all know that nuclear waste can be very hazardous if not disposed off without treating properly. Over the years, many disasters like the Kyshtym nuclear disaster, the Chernobyl disaster, the Fukushima Daiichi nuclear disaster etc. have led to millions of casualties and  loss of property etc. These could have been prevented, had proper treatment processes been implemented. Hence, in order to further improve the treatment processes, I suggest the use of LASER. As we all know, high intensity LASER can directly produce nuclear excitations. This can alter the half-life and decay periods of nuclei. Hence, this idea can be effectively used to treat nuclear waste in future.

The European Union has spent  about 700 million euros ($900 million) to build the world’s most powerful lasers, technology that could destroy nuclear waste.

The Extreme Light Infrastructure project has obtained funding for two lasers to be built in the Czech Republic and Romania. A third research center will be in Hungary. The power of these LASERs are 10 times more than any ever built and these have the capacity to deteriorate the radioactivity of nuclear waste in few seconds.

And the last but not the least, mother earth should also be taken care of. Among all the types of wastes possible,  nuclear waste causes greatest harm since it is something which is not natural (or disposable). It has a specific treatment, and thus, according to us, use of laser technology can make a revolutionising improvement in this field.

 The femtosecond laser has now been adapted for intraocular use through the integration of intraoperative ocular coherence tomography (OCT) (Figure ).

The use of OCT diagnostics has been vital in mapping out anterior segment dimensions of the eye to ensure accurate laser application to the anterior capsule for capsulotomy and lens fragmentation. The technology is expensive, but the rationale for use is the overall benefit to patients.

Presently there are four commercial systems on the market, Victus (Bausch+ Lomb – Technolas), Catalys (Abbott Medical Optics – Optimedica), Lensx (Alcon) and LensAR (LenAR). Each device has its strengths. However, the only device that in addition to cataract surgery provides the ability to perform corneal flaps for Lasik and therapeutics such as channels for intracorneal rings and corneal transplant is the Victus femtosecond laser (Figure ).

THE VICTUS FEMTOSECOND LASER in use for CATARACT SURGERY

LASER REFRACTIVE EYE SURGERY

CATARACT SURGERY WITH FEMTO-SECOND LASER'S

7.Giant VULCAN LASER transmutes isotopes

Over the past four decades LASER has proved its efficacy and reliability in retinal phototherapy and has evolved as therapeutic coherent light source. It has induced many beneficiary retinal biochemical and physiological changes.The concept that refractive error could be corrected by sculpting corneal stromal  tissue to change its curvature was the brainchild of Barraquer Moner in 1948.He developed the process of “keratomileusis”(Greek: milling of the cornea).However, the techniques have improved over the years and allow us to extend a range of prescriptions suitable for refractive surgery.We will discuss these new LASER technologies and methodologies that limit photocoagulation damage by using barely visible treatment endpoints, reducing irradiance, utilising repetitive laser pulses(micropulse photocoagulation), as well as optimising laser treatment wavelength

In future,the preoperative diagnostics may be integrated into the lasers used for laser refractive surgery or lasers used for cataract/refractive lens exchange.Intraoperative diagnostics should confirm lens power and refractive outcome before completion of the surgical case. One such system,trying to achieve the same is the ORA system (Wavetec) which, using aberrometry, measures intraoperative refraction once a lens is removed and also when the lens is implanted. The system has application in confirming appropriate lens power in those who have had previous laser eye surgery where lens calculation using conventional biometric methods can be quite challenging

Pixel Optics digital eyewear may well replace traditional progressive lenses. Containing a layer of transparent liquid crystal, these new lenses electronically alter how the lenses refract light, meaning they will adapt from reading the paper to driving in 0.025 seconds.

LASER eye surgery pioneers say that femto-second LASER's will make human eyesight upto five times better in the future.

LASER eye surgery is to a great extent enhancing the quality of our vision,the most valued of our senses.

“When we alter the quality of people's vision we alter the quality of people's lives, it's a life-changing experience”(Dr.Rosen, 2012).

There has been major technological development in the last 20 years. These could be grouped in the following categories:

Broad beam lasers to flying spot lasers

Microkeratomes

The improved accuracy of manual microkeratomes has improved the safety of the procedure.Femtosecond laser to replace manual microkeratomes for flap cutting has further improved safety by improving precision and avoiding intra-ocular complications related to flap cutting with manual microkeratomes.

One key breakthrough has been the development of a new procedure called ReLEx SMILE or Refractive Lenticule Extraction. Ever since femtosecond (infrared) lasers were first introduced into refractive surgery, the ultimate goal has been to do flapless laser eye surgery - keyhole surgery (Reinstein P. D., 2014).

The second major breakthrough has been Laser Blended Vision, which enables us to avoid the older technique of having to do a clear permanent lens replacement inside the eye.

REVIEW OF LITERATURE

As mentioned in an article on the advances of LASER eye surgery (Sagar refer citation 3) the ‘brand new thing’ in the world of refractive lens exchange surgery is the introduction of the femtosecond laser. It has now been adapted for intraocular use through the integration of intraoperative ocular coherence tomography (OCT).The ultra short beams of the femto-second LASER's are precise enough to avoid damaging healthy material and have been proven to offer a safer option to existing practices. .

 According to a recent journal(Sagar write citation 5) LASER blended Vision is a corneal laser eye surgery like LASIK that takes about 10 minutes to perform in both eyes, heals in a few hours and can correct 97% of all people with bifocals orreading glasses.

Small Incision Lenticule Extaction (SMILE) technology has several advantages. It avoids flap-related complications. It also has less biomechanical impact on the cornea because it preserves the strongest part of the cornea (the front) while the tissue removal comes from deeper down (the weaker fibres).(Sagar write citation 7)