Looking into the fundus of the eye, one sees the back of the interior eye including the retina, macula, and the optic disc. The macula contains the highest concentration of cone cells responsible for sharp visual acuity in bright light conditions, as opposed to rod cells which function in dim lighting for peripheral vision. The slight yellowish tinge of the macula comes from zeaxanthin and lutein, pigments derived from our diet. The optic disc is where arteries enter to supply blood to the retina; the optic nerve is formed at the optic disc which sends information to the brain. There are no cones or rods at the disc, so this is the “blind spot”.
The distribution of arteries and pigmentation is unique in each individual, which can be used as a “fingerprint”. The fundus can show the health of the individual, and so each participant in the Canadian Longitudinal Study on Aging (CLSA) will have their retinal pictures taken every three years.
This is my right eye.