The term ‘Uvea” was first used by Galen, a Roman physician, to include both the choroid and the iris, because they resemble a grape from which the stalk had been torn out leaving a hole in front, the hole being the pupil of the eye.
Only about 2% of the population has green eyes.
The idea for the general principle of a contact lens was made by Leonardo da Vinci in 1508.
Swiss physician A. E. Fick is credited with fitting the first glass contact lens in 1887.
The retina has 10 separate layers. The cornea has 5 separate layers.