Nearsighted individuals typically have problems seeing well at a distance
and are forced to wear glasses or contact lenses. The nearsighted
eye is usually longer than a normal eye, and its cornea may also be steeper.
Therefore, when light passes through the cornea and lens, it is focused
in front of the retina. This will make distant images appear blurred.
There are several refractive surgery solutions available to correct nearly
all levels of nearsightedness.
Farsighted individuals typically develop problems reading up close before
the age of 40. The farsighted eye is usually slightly shorter than
a normal eye and may have a flatter cornea. Thus, the light of distant
objects focuses behind the retina unless the natural lens can compensate
fully. Near objects require even greater focusing power to be seen
clearly and therefore, blur more easily.
LASIK, Refractive Lens Exchange and Contact lenses are a few of the options
available to correct farsightedness.
Asymmetric steepening of the cornea or natural lens causes light to be
focused unevenly, which is the main optical problem in astigmatism.
To individuals with uncorrected astigmatism, images may look blurry or shadowed.
Astigmatism can accompany any form of refractive error and is very common.
Astigmatism can be corrected with glasses, contact lenses, corneal relaxing
incisions, laser vision correction, and special implant lenses.
Presbyopia is a condition that typically becomes noticeable for most
people around age 45. In children and young adults, the lens inside
the eye can easily focus on distant and near objects. With age, the
lens loses its ability to focus adequately.
Although presbyopia is not completely understood, it is thought that the
lens and its supporting structures lose the ability to make the lens longer
during close vision effort. To compensate, affected individuals usually
find that holding reading material further away makes the image clearer.
Ultimately, aids such as reading glasses are typically needed by the mid-forties.
Besides glasses, presbyopia can be dealt with in a number of ways.
Options include: monovision and multifocal contact lenses, monovision laser
vision correction, and new presbyopia correcting implant lenses.
