Emmetropia is the term used to describe an eye that requires no correction
to allow for sharp, clear vision at all distances. As light passes into the eye, it is directed into one sharp
point of light that falls on an area of saturated visual receptors on the back of the eye called the fovea or macula.
The lens of the eye bends to help focus the eye on objects that are near and relaxes to focus on things far away allowing
for good vision at a large range of distances.
Far-sightedness or Hyperopia
This is a condition in which patients have difficulty focusing on objects
that are near. This condition is often confused with presbyopia. As light passes into an eye with hyperopia,
the light is focused into one sharp point that falls behind the fovea or macula on the retina. However, due to
the focusing ability of the eye, some patients can still achieve good distance vision by straining his or her eyes
to see. Although distance vision may be unaffected, reading and computer work suffer because there is not
enough focusing ability left to see clearly at near. Eyestrain caused by this excessive focusing may cause headaches
or double vision. Glasses or contact lenses are prescribed to allow for comfortable, relaxed distance vision so that
the focusing needed for near is within the normal range.
is the condition in which a patient loses the ability to focus on near objects around the age of 40. Presbyopia occurs
because the lens in the eye becomes less flexible as the aging process progresses. This loss of flexibility results
in an inability of the lens to change the point of focus from a distance object to a near object. As a result, reading
or bifocal glasses are prescribed to focus the light onto the macula or fovea while viewing a near object.