Keep reading to learn more about these procedures. This is normally caused when the cornea is too steep or the eye is too long. Hyperopia, or farsightedness, occurs when the eye does not have enough focusing power and light focuses behind the retina instead of on it. The eye is either too short or the cornea too flat. Astigmatism is an uneven curvature of the cornea that causes blurred vision.
Different curves result in more than one focal point, and thus, distorted vision.
Presbyopia is not, strictly speaking, a refractive error. It occurs in all people as they age, and is manifest by the need for reading glasses around the age of forty. This allows the detection of corneal conditions such as keratoconus that may exclude you from being a refractive procedure candidate. What to Expect During and After Surgery Numbing drops, not needles, are used to anesthetize your eye. Antibiotic drops to prevent infection before and after the procedure are also used.