HYPEROPIA (“Longsightedness”)

WHAT IS HYPEROPIA?

When light rays from a distant object (6 m or further away) come into focus behind the retina in an unaccommodated eye, we say that the eye is hyperopic (or hypermetropic),or that the person is hyperopic. Hyperopia is sometimes also called “longsightedness” or“farsightedness”.The light does not truly focus behind the eyeball, but it would if the back of the eye did notblock the light rays.

Figure 1 shows light from a distant object focussing at a focal point behind the retina of a relaxed, hyperopic eye.

Figure 1The focal point in a relaxed hyperopic eye is behind the retina

CAUSES OF HYPEROPIA

Hyperopia may be caused by:

• an eye that is shorter than average (called axial hyperopia)
• a cornea and/or crystalline lens that is too flat (not curved enough) and, therefore, too weak in power (called refractive hyperopia)

CORRECTION OF HYPEROPIA

Hyperopia is corrected with convex (or “plus”) spherical lenses. When we correct

hyperopia, we are decreasing the need for the eye to accommodate by using positive spectacle lenses.