The human eye receives optical stimuli and transmits them to the brain. Like a camera, it has an optical system and a photosensitive layer. The optical system of the eye consists of the cornea and the eye lens, with the cornea responsible for two thirds and the lens for one third of the refractive power.
If the eye is “too long,” it is called myopia, and if it is “too short,” that error is called hyperopia. In European countries, 15-20% of the population is short-sighted and about 5% are far-sighted.
If the light rays striking the eye mistakenly focus in front of the retina, this eye is called short-sighted. Usually this is due to an eye which is physically “too long”. Objects in the distance are perceived only vaguely because the image that creates the optics is not on, but in front of the retina. Nearby objects are displayed on the retina and thus sharply.