Normal vision

The cornea, the crystalline lens, and the vitreous body form the optical system, which guides incoming light rays so that they converge exactly on the retina. If this is the case, everything you see is reproduced clearly on your retina, your eye sight is normal.

If the image formed is blurred there is a sight defect (ametropia). Nowadays most sight defects can be corrected by refractive surgery.

The following sight defects exist:
- Myopia (nearsightedness)
- Hyperopia (farsightedness)
- Astigmatism (unequal curvature of the cornea)
- Presbyopia (impairment of vision with age)

Normal vision Myopia Hyperopia Astigmatism Presbyopia Special lenses to correct / avoid residual defects Suitability for refractive surgery