The art and science of sight & looking into ones eyes

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Eyes have always intrigued us. Eyes reflect our intent, emotions, wisdom, and even romance. While science attributes eyes with sight, for art and literature these are windows of our thought and vision. Indeed, these are two windows of our soul, be it thoughts of wisdom benevolence, mischief or cruelty. Since time immemorial, looking into ones’s eyes is both a literary metaphor, and also as a branch of science.

Eyes: An apparatus for sight

Eyes are spherical or a globe shaped organs. Only a part of this globe is visible between the two eyelids. Most of its outer cover is white – sclera. Central part is coloured, due to a muscle named iris. In different people, iris varies from brown, black, green and even blue. While, the outermost protective covering over the central coloured part is called cornea, the covering over the sclera is conjunctiva. Together these transparent covers, cornea and conjunctiva protect our eyes.

Light enters inside our eyes

Different objects reflect light, that falls on them. This light enters our eyes through a small hole in the middle of Iris, which is pupil. Quite like a camera, our eyes can adjust amount of light that enters our eyes. If light is bright, pupils will contract and hole will be small. If light is dull, or in dark, pupil dilates.

Just behind the pupils is the lens. This transparent lens sits on a capsule and refracts the light to fall on the retina. The space between the cornea and the lens-capsule is anterior chamber. The space behind the capsule is posterior chamber. These two chambers are filled with transparent fluid.

Signal for sight

Retina has cells, rods and cones. As light falls on retina, these cells capture the light and convert it into a signal. This nerve signal is then transmitted through a large optic nerve to the brain.

Optic nerve connects eyes to the brain. The signals from optic nerve enter posterior part of brain. In turn, brain processes these signals as images. Our brain can identify colour, shape and size of different objects, can recall previous seen images, to interpret the current seen object.

Treating diseases of eye in ancient times

Ancient Indians, Egyptians and Greek have all written in great depths about diseases of eyes and their remedies. Ancient Indian text Uttara Tantra, attributed to Sushruta lists about 76 diseases of eyes and its remedies.

Ancient texts describe structure of eyes, as a lens that stands between two fluid filled spaces – the anterior and the posterior chambers. We find many references for cataracts, and the process of removal of ripe lens in these ancient texts.

While ancient Greeks believed that eyes emit rays that help us to see, by middle ages Unani or Persian physicians had refuted this claim. Probably the saying “light of the eyes” comes from this ancient concept of eyes emitting some kind of light. Rather, light enters the eyes from the outside and helps us to see. This discussion about process of sight, is well described by Ibn Al-Haytham (also known as Alhazen in Latin; 965-1040) through his Book of Optics (Kitab al-Manazir). Opthalmology was one science that flourished even during the dark ages.

What is in a name – “Ocular” , “Opthalm“, and “Optic“

Latin word for eye is Oculus, and the Greek word is Opthalmia or Obtalmia. In 16th-18th centuries, physicians who specialised in diseases of eyes, were often referred to as oculists. Use of the words Oculi, Oculate or Ocular for eye, process of seeing, or belonging to the eye are more older. These words were more often used in the religious and literary works. Today in medicine we use this word in context of movement of eye, eg ocular movements, extra-ocular muscles or Oculomotor nerve.

The first use of the word Opthalmia was in 1398 for diseases of eye. Later in 1696, the word Opthalmist and in 1834 the word Ophthalmologist first appeared in medical literature. Ophthalmologists are doctors that specialise in diseases and treatments of diseases of the eye. We use this word for eye specialists.

Another word Optic (previous Obtyke, Obtick or Optick) is a French adjective for “pertaining to eye” or “assisting with sight”. It was first used in 1541. We use this word for Opticians or Optometrists who assist with visual aids. This word is also used in a figurative manner as “optics” of an action, policy or a viewpoint. In medicine, this word is used for nerve that carries fibers that air in vision, eg optic nerve, chiasma or fibers.

Advances in Early modern era (1400-1800)

Oculists, that included both the eye physicians, as well as Optometrists, those who worked with lenses, helped improve our understanding of eye diseases. First spectacles came into use in the 13th century. In 1250 Roger Bacon described grinding of Beryl to make ‘reading stones’. These were first used by clerics who had problems with their eyesight. All these lenses were convex, and good for near-sightedness. In 1451, a German priest Nicolas de Cusa described that a concave lens could be used for Myopia or far-sightedness.

Andreas Vesalius (1514-1564) discovered that the human crystalline lens, when removed, functioned as a convex lens. In 1650s, Antonie Leeuwenhoeck was working on lenses, and invented a first microscope. World of lenses was now in an advanced stage. We continue to use such devices to magnify and also for a better sight.

Technique of cataract surgery also improved in this period. Previously, opacified lens could be removed in a piecemeal fashion. In 1707 Charles Saint Yves (1677-1731) performed first full cataract extraction. A few years later, a French ophthalmologist Jacques Daviel (1696-1762) modified the previous technique and performed cataract extraction, by keeping touter capsule of the lens intact. These pioneers established French school of ophthalmology.

Modern era of Ophthalmology and birth of ophthalmoscope

In early 1812, Georg Joseph Beer (1763-1821) established first department of Opthalmology in Vienna Medical School. He also successfully advocated to introduce ophthalmology as a subject of mandatory instruction for all medical students. In next few years, we had dedicated ophthalmology hospitals across cities in Europe.

Hermann von Helmholtz (1821-1894) was a German physicist and a physician. He was a teacher of anatomy at the Academy of Arts in Berlin in 1848, and later a professor in anatomy at Bonn and then at Heidelberg. In 1871 he was appointed as a professor of Physics. In 1851 he invented ophthalmoscope.

Ophthalmoscope enabled physicians to look inside the eye, and with a sufficient magnification. This provided unprecedented diagnostic capabilities and revolutionised the practice of ophthalmology. His book Handbuch der Physiologischen Optik is a classic text for ophthalmologists. He also worked extensively in field of acoustics and electromagnetism.

With advent of ophthalmoscope, for the first time, ophthalmologists were able to unravel the mysteries of the inner eye. They could also reveal the links between eye manifestations and systemic diseases.

von Graefe and his legacy

Albrecht von Graefe (1828-1870), was a German ophthalmologist who began practicing in 1850, around the same time Helmholtz had invented an ophthalmoscope. He made important surgical discoveries such as excavation of the optic disc in glaucoma (1855), and iridectomy in glaucoma (1857). Eponym von Graefe’s sign seen in Graves disease is named after him. He also founded the journal Archiv für Ophthalmologie in 1854 and German Ophthalmological Society in 1857.

Famous European ophthalmologists

In 1972, Hungary issued a two-stamp set that has featured six ophthalmologists. All these six are from an era of new discoveries.

Gullstrand was a Swedish ophthalmologist. He was awarded Nobel Prize in medicine for his work on optical images and of the refraction of light in the eye, in 1911. He later served on the board of Royal Swede Academy of Medical Sciences, a body that recommends Nobel Prizes. VP Filatov was a Russian eye surgeon. He pioneered corneal transplant. Jules Gonin was a Swiss ophthalmologist. He performed the first surgery for Retinal detachment. While Gonin was recommended for a Nobel prize, he died in 1935.

The last three ophthalmologists on the above stamp are Hungarians. Imre Joseph (1884-1945) was the head of Ophthalmology at the University of Budapest in 1939. He specialized in intracapsular 
cataract extraction, corneal transplantation and retinal detachment surgery. Emile de Grosz (1865-1941) was a cataract surgeon and a professor at the University of Budapest in 1904 and then dean of
Budapest Medical School in 1914. Ladislas de Blaskovics (1869-1938) was an oculoplastic surgeon and was professor of ophthalmology at the second University  Eye Hospital in Budapest.

Pinto and Barraquer (Portugal and Spain)

Gama Pinto (1853-1945) was a Portuguese ophthalmologist, who was born in Goa, and who studied at Lisbon. He founded the Institute of Ophthalmology, at Lisbon the first training centre for ophthalmologists in Portugal. This institute bears his name. 

Ignacio Barraquer (1884-1965)  was an ophthalmologist from Spain. He conceived the idea of extracting cataracts by means of a delicate and subtle application of a suction cup without damaging the tissues.

Important inventions in ophthalmology

Many important inventions in ophthalmology, were done in the 20th century. These include the following:

Invention	Year	Scientist
Corneal transplant	1905	Eduard Zirm
Slit lamp	1911	Allvar Gullstrand
Ishihara color test	1917	Shinobu Ishihara
Gonioscopy	1918	Alexios Trantas
Goldmann perimetry	1945	Hans Goldmann
Intraocular lens	1949	Harold Ridley
B-scan USG	1958	Gilbert Greenword
Laser photocoaguln	1960	Theodore Maiman
Fluorescein angio	1961	Harold David Alvis
LASIK	1989	Gholam A Peyman

Era of precise instruments in eye surgery

Eye surgery today requires advancements in equipment both for diagnostics and for treatment. Amongst many optical instrument manufacturers, Zeiss is a leading innovator and manufacturer. Carl Zeiss (1816-1888) was a German scientific instrument manufacturer. After completing his education in mechanical engineering, he established a workshop for precision machinery and optics in 1846, in Jena Germany. He started making microscopes, that were sold across Europe.

Ernst Abbe (1840–1905), a private docent, or associate professor, at the university and 25 years younger to Zeiss. The two partnered to revolutionise microscope technology, and add multiple lens eye piece and objectives. Ernst Abbe honored the contributions of Carl Zeiss in several major speeches and created a memorial with the foundation of the Carl Zeiss Foundation, Carl-Zeiss-Stiftung, in 1889.

First operating microscope was used by Carl Olof Nylén (1892–1978), in 1921 for an ear surgery. In 1946 such an instrument was used by Richard A. Perritt for eye surgeries. In 1953 Zeiss brought out its first operating microscope, that had a mechanical arm. Todays operating microscopes, have much improved optics, magnification distance, as well as ease of use.

Today ophthalmology has progressed. The ophthalmoscope has advanced to fundus camera (1955). Now we also have photocoagulators (1957) for the treatment of retinal detachment and Ophthalmic Workstation (1985) for various complex surgeries. Since 1999 we have an IOLMaster, so that can make precise non-contact measurement of the eye prior to cataract surgery. Since 2000 refractive surgeries have expanded, and have added another dimension to growing field of ophthalmology.