WHAT’S ASTIGMATISM?

Astigmatism is type of refractive error like Hyperopia and Myopia.  Though astigmatism can occur by itself, it is most commonly found in combination with myopia or hyperopia. Myopia occurs when the cornea is too steep; hyperopia, when it is too flat. Astigmatism occurs when the cornea is warped.  Astigmatic corneas are shaped more like a tablespoon where normally the cornea is shaped more like a soup spoon (oval versus spherical shape) or where one side is steeper in curvature than the other side.  This creates two focal points for the eye.

WHAT’S HYPEROPIA?

Hyperopia is also known as “farsightedness.” It usually means that one has better distant vision than near vision. It is very common.  In fact, the majority of the United States population is farsighted. Hyperopia tends to mostly affect the young under 10 years old and people age 45 and above. The condition is characterized by an eye that is too short in length, or where the front of the corneal curvature is too weak.

WHAT’S MYOPIA?

Myopia, or nearsightedness, manifests as distant blur, while near vision remains relatively unaffected. It’s caused by the eye focusing an image short of the retina at the back of the eye. There are three components that determine the eyes’ focusing behavior; the cornea, the lens and the length of the eye. The cornea, the clear part of the eye on the front surface, bends 70-80% of the incoming light into the eye. The lens, located inside the eye behind the cornea, is responsible for fine focusing the bends 20-30% of the incoming light. The eye length, from front to back, can also affect where the light focuses.