Hyperopia (farsightedness)
People with hyperopia tend to see distant objects
clearly or more clearly than objects up close, which are blurry. This is
because the light rays don't get a chance to come into focus before they
reach the retina. Hyperopia is a refractive disorder.
Causes:
Generally this disorder occurs because there is less
distance between the cornea and retina than in a normal eye. This shorter
eyeball therefore causes most light rays, especially those from nearby
objects, to reach the retina before coming into focus. The hyperopic
eyes' refractive power is too weak.
When viewing objects far away, the lens of a normal
eye is pretty flat. However, the lens of a farsighted eye cannot
accomodate, or change its shape, enough to make the near vision clear.
Often, the lens must accomodate even when seeing at far distances. This
extra work that a hyperopic eye must do can cause eyestrain and headaches.
Correction:
Eyeglasses or contacts with convex lenses (thick in
the middle and thin at the edges) are prescribed to help focus nearby
light rays on the retina. There are also some laser surgery options
available to restore farsighted vision partially, or even fully in some
cases.
