Insights into Optics by Yousef Zafer https://padlet.com/yousefzafer/MM1 Mini Museum #1 en-us 2022-03-25 13:38:44 UTC 2025-10-29 17:05:51 UTC hello@padlet.com Rufus of Ephesus localizes optic chiasm yousefzafer https://padlet.com/yousefzafer/MM1/wish/2113911017
Although he's not as well known as his predecessor Hippocrates, Rufus of Ephesus (80-150 C.E) was an instrumental figure in the development of neuroanatomy, specifically relating to the anatomy of the 3rd ventricle and optic chiasm 2. He was among the first to describe the optic chiasm, name it, and know of its involvement with vision around 100 C.E1. 

The optic chiasm is absolutely essential for processing visual stimuli as it's the intersecting point between both optic nerves. Approximately 1/2 the axons in each optic nerve pass through the opposing tract at the optic chiasm. This is important to note because vision uses contralateral processing, where visual stimuli is processed on the opposite side of where it was detected. The optic chiasm is a good representation of the deep complexity of the brain. Its initial discovery was crucial to understanding how the brain processes visual stimuli and many visual deficits as well.


Sources:
  1. Costea, C., Turliuc, S., Buzduga, C., Cucu, A, Dumitrescu, G., Sava, A, Turliuc, M. (2017). The history of optic chiasm from antiquity to the twentieth century. Childs Nervous System, 33(11), 1889-1898. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5644697/.
  2. Bujalkova, M. (2011). Rufus of Ephesus and his contribution to the development of anatomical nomenclature. Acta Med Hist Adriat, 9(1), 89-100. https://pubmed.ncbi.nlm.nih.gov/22047484/
]]> 2022-03-25 14:28:11 UTC https://padlet.com/yousefzafer/MM1/wish/2113911017 Ibn Al Haytham publishes The Book of Optics, influences scientific method, perspective, art. yousefzafer https://padlet.com/yousefzafer/MM1/wish/2114036533 1011 C.E Ibn al-Haytham publishes his 7 volume Book of Optics which influenced multiple disciplines beyond neuroscience. His ideas were studied by Da Vinci, Galileo, Descartes, Kepler, and Newton who built upon his work1. Al-Haytham's most important contribution to the field of science was his theory of vision, the physiology of the eye and psychology of perception. For example, using a camera obscura he was able to prove light travels in straight lines, and show that light rays reflect differently off of plain vs. curved surfaces1. In modern times we use laser beams to manipulate atoms and use light to influence neurons in optogenetics, and other associated advances can be attributed to the Book of Optics written roughly 1000 years ago1.

The Book of Optics had a tremendous impact on how Renaissance artists used perspective to create the illusion of 3 dimensional depth on canvas2. The artists had the same objective as Ibn al Haytham in that they both wanted to understand the objective world and the visual system which brings it into our consciousness.



Sources:
  1. Al-Khalil, J. (2015). Book of Optics. Nature, 158, 164-165. https://www.nature.com/articles/518164a.pdf
  2. Science of Art and Perspective. Web Exhibits, 1-4. http://www.webexhibits.org/sciartperspective/perspective3.html
]]> 2022-03-25 15:37:36 UTC https://padlet.com/yousefzafer/MM1/wish/2114036533 Salvino D'Armate invents eyeglasses yousefzafer https://padlet.com/yousefzafer/MM1/wish/2114039701 1284 C.E Salvino D'Armate of Florence, Italy invents the eyeglass and offers those with visual deficits a reliable treatment option. D'Armate hurt his eye when viewing a light refraction and came up with the idea to look through two convex glass pieces which improved his quality of his vision1.

Glasses are important because they focus light on the correct spot in the retina, generating the clearest image1. This actually helps correct poor vision over time instead of only being a temporary fix. The first glasses corrected both hyperopia and presbyopia, the latter of the two develops with age. And because the shape of our eyes is unique, it means that while a pair of glasses may help one person see, the same glasses may hinder another persons sight. The first glasses to correct myopia were developed in the 15th century and were the first to sit on the bridge of the nose; and stems which go behind the ear were invented in the 17th century1.

Sources:
  1. Al-Amiri, M., El-Gomati, M., Zubairy, S. (2016). Optics of Our Time. Springer Nature.  https://link.springer.com/content/pdf/10.1007/978-3-319-31903-2.pdf
]]> 2022-03-25 15:39:24 UTC https://padlet.com/yousefzafer/MM1/wish/2114039701 John Dalton provides the first scientific description of colorblindness yousefzafer https://padlet.com/yousefzafer/MM1/wish/2114044401 John Dalton is best known for his atomic theory, but it's often forgotten that he also was the first to offer a clear, scientific description of color blindness in 1798 C.E 1. John Dalton himself was color blind. He described how he ultimately came to the conclusion he was color blind. Dalton said he had read that the flower geranium zonale was pink colored, but it appeared to him to be a sky blue color. And in the candle light the same flower appeared to be what he called red, because of its contrast to blue. He also described blood as being bottle-green, and grass as red 1. Dalton described it:

  • "I see only two or at most three distinctions these I should call yellow and blue; or yellow, blue and purple. My yellow comprehends the red, orange, yellow and green of others; and my blue and purple coincides with theirs. That part of the image which others call red appears to me little more than a shade or defect of light; after that the orange, yellow and green seem one colour which descends pretty uniformly from an intense to a rare yellow, making what I should call different shades of yellow. The difference between the green part and the blue part is very striking to my eye: they seem to be strongly contrasted. That between the blue and purple is much less so. The purple appears to be blue much darkened and condensed 1."

There are currently four main types of color blindness. Achromatopsia, or total color blindness. Protan, or red color blindness. Deutan, or green color blindness. And lastly, tritan, or blue color blindness. Experts say Dalton was most likely a protanope1.

Sources:
  1. Emery, A. (1988). Portraits in medical genetics. Journal of Medical Genetics, 25, 422-426. https://jmg.bmj.com/content/jmedgenet/25/6/422.full.pdf

]]> 2022-03-25 15:41:55 UTC https://padlet.com/yousefzafer/MM1/wish/2114044401 Jacques Daviel performs the first cataract extraction on a living human eye yousefzafer https://padlet.com/yousefzafer/MM1/wish/2114069606
There is some controversy as to who performed the very first cataract extraction surgery. Because an Indian surgeon named Sushruta described an extracapsular cataract extraction in his literature as early as 600 B.C.E 2. But the first true cataract extraction, as we know it today, was performed on a living patient in 1747 C.E by Jacques Daviel in Paris, France 2. He understood the correct anatomical location of the lens and the true nature of the cataract. It's a bit ironic because Daviel had little surgical experience and was best known for his couching prior to developing this technique. Daviel's technique was revolutionary because his procedure had a success rate of roughly 50% which was much more effective than couching. He would make a 10mm incision puncturing the lens capsule, exposing the nucleus, and then extracting the lens cortex via curettage2. The procedure had great success compared to couching, but there were still significant post op issues such as poor wound healing and infection until anesthesia and hygiene are accounted for. Despite this, Daviel's surgery remained the acceptable approach for cataract extraction for over 100 years1.

Sources:
  1. Leffler, C., Klebanov, A., Samara, W., Grzbowski, A. (2020). The history of cataract surgery: from couching to phacoemulsification. Annals of Translational Medicine, 8(22), 1551. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7729313/
  2. Davis, G. (2016). The Evolution of Cataract Surgery. Missouri Medicine, 113(1), 58-62. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6139750/
]]> 2022-03-25 15:56:38 UTC https://padlet.com/yousefzafer/MM1/wish/2114069606 George Bartisch, the father of opthamology yousefzafer https://padlet.com/yousefzafer/MM1/wish/2114079395
My docent is George Bartisch, born to a lower class German family in 1535. He is often referred to as the father of opthamology, though he lacked any formal education. He published Opthalmodouleia in 1583. It was the first systematic work on ocular disease and ophthalmic surgery and the first ophthalmic atlas. Bartisch included 92 full page woodcuts, which he drew himself1. They're unique because of how he was able to make the illustrations have layers, or flaps, to imitate dissection, not just of the eye, but of the face and brain as well with incredible detail. Modern ophthalmology is forever in debt to to the German physician for his contributions and innovations.

He was also a very superstitious man, as was common at the time. He believed some malformations and diseases of the eye came from devils or spells, especially if they caused pain1. And interestingly, he was opposed to the use of glasses or monocles as he believed they weakened vision1.

Sources:
  1. Thomas, T. (2015). George Bartisch: An Inventive Look Into Ophthalmodouleia. UTHSCA Libraries. https://library.uthscsa.edu/2015/01/george-bartisch-an-inventive-look-into-ophthalmodouleia/




]]> 2022-03-25 16:02:40 UTC https://padlet.com/yousefzafer/MM1/wish/2114079395 Cataract surgery then vs. now yousefzafer https://padlet.com/yousefzafer/MM1/wish/2114089771 Couching is the earliest recorded type of cataract surgery dating back to 800 B.C.E in India . It's a procedure where the cataractous lens is removed from the visual axis into the vitreous cavity1. As I described earlier in the padlet, couching was not always successful and was later replaced by cataract extraction surgery; invented in 1747 Paris, France by  surgeon Jacques Daviel.

Fortunately, today there are much better techniques which built upon Jacques Daviel's cataract extraction surgery. Phacoemulsification, which was developed by Charles Kelman in 1967, uses ultrasonic vibrations to break the cataract into small particles, which are then removed via aspiration1. This modern approach is the most commonly used because it's minimally invasive. Small incision sutureless cataract surgery is another modern option for those who are at risk for corneal damage or where phacoemulsification is not possible1. This surgery uses a very small incision which doesn't require sutures and is much less invasive than Daviel's approach which used a large incision in order to extract the cataractous lens.

I linked a video to an animated cataract surgery here:
https://www.youtube.com/watch?v=n_3cG9oeuNo

Sources:
  1. Reddy, R. (2019) Evolution of Cataract Surgery: Types of Surgery and Advantages of Technological Advancements. NeoRetina Eyecare Institute. https://neoretina.com/blog/evolution-of-cataract-surgery-types-of-surgery-and-advantages-of-technological-advancements/

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