|
 |
This is a ``normal" eye.
Light rays are focused
perfectly onto the retina |
This is when all rays of light are focused by the cornea and lens perfectly on the retina. Distance and near vision are both sharp.
.
 |
This is a Myopic
(nearsighted) eye.
Light rays are focused
too much and fall
in front of the retina. |
Myopia occurs when the rays of light are focused in front of the retina. This causes blurred distance vision. Near
vision is clear but the range of clear near vision depends on the level of nearsightedness. Nearsightedness usually occurs when a person's eye is too long. A concave lens (either in the form of an eyeglass or contact lens) in front of the eye is needed to correct myopia. Laser vision correction can be performed to effectively flatten the cornea in order allow parallel light rays from 20 feet and beyond (infinity) to be focused sharply on the retina.
 |
This is an Astigmatic eye.
Light rays are focused onto
two separate points instead
of one causing blurred vision. |
This occurs when a person's cornea has the shape of a football instead of being perfectly spherical like a basketball. This causes rays of light perpendicular to each other to be focused differently within the eye. Astigmatism leads to blurred, tilted vision. A cylindrical lens (either in the form of an eyeglass or contact lens) in front of the eye is needed to correct astigmatism . Laser vision correction can be performed to effectively steepen the flatter meridian (or flatten the steeper meridian) of the cornea in order allow parallel light rays from 20 feet and beyond (infinity) to be focused sharply on the retina. This essential turns a football-shaped (astigmatic) cornea into a basketball-shaped (spherical) cornea.
 |
This is an Hyperopic
(farsighted) eye.
Light rays are not focused
enough onto the retina.. |
)
Hyperopia occurs when rays of light are focused behind the retina. This causes blurred distance vision if a person is unable to compensate by internal focusing. Near vision is blurred. Farsightedness usually occurs when a person's eye is too short. A convex lens (either in the form of an eyeglass or contact lens) in front of the eye is needed to correct hyperopia. Laser vision correction can be performed to effectively steepen the cornea in order allow parallel light rays from 20 feet and beyond (infinity) to be focused sharply on the retina.
When most people reach their forties, they have to hold printed material at arm's length to read clearly. This is the result of an age related condition called presbyopia.
Prebyopia is a universal condition associated with the eyes' diminishing ability over time to focus on close objects. It is neither a disease nor a defect. People usually discover this trouble during their mid-forties, and can correct it with lenses adapted to their various needs. Although presbyopia is a natural condition that everyone has to face sooner or later, proper diagnosis, eye care, safety precautions and monitoring of the condition can give our eyes a new lease on life!
Refractive surgery such as LASIK or PRK will not halt presbyopia. In fact, whether or not you have had eye surgery in the past, by your mid-forties you will likely find you need corrective eyewear.
When presbyopia is corrected with single-vision eyeglasses, one to three pairs may be required, depending on the wearer's needs (for instance, one for reading and one for driving). Reading glasses, bifocals, trifocals or the newer progressive lenses are also available.
Progressive, or "no-line" lenses are becoming increasingly popular, as they disguise the fact that you are wearing reading glasses while providing clear vision up close, far away and at every point in-between. The latest models are custom fit by our trained Family Eye Care Center staff to suit the special requirements of your work, leisure, hobby or home environment. They are the next best thing to natural vision, so you are easily able to adapt to them.
|
