Why do some people see clearly at all distances and others have trouble seeing near or far distances?
Visual problems are often caused by irregularities or changes over time in the eye’s cornea or lens or in the shape of the eye itself. These irregularities and changes prevent the eye from focusing correctly, which causes blurry vision.
There are several common types of vision problems:
Nearsightedness, or myopia, is when a person is able to focus clearly on near objects but distant objects are blurry.
Farsightedness, or hyperopia, is when someone can focus clearly on distant objects but near objects are blurry.
Astigmatism is a type of refractive error that causes blurriness at all distances.
Presbyopia, often confused with farsightedness, occurs slowly over time, as the lens and muscles of the eye lose their ability to focus sharply on near object, making it difficult to read or see fine details up close.
Cataracts are another common vision problem that can cause blurry vision, difficulty seeing in low light and at night (frequently experienced with night driving), and problems distinguishing colors.
Glasses and contact lenses are the most common treatments for refractive errors, but they can be lost or broken and interfere with activities you love. Fortunately, there are surgical solutions for vision problems that can deliver reduced dependence on glasses and contacts-sometimes permanently.
As you look at objects, light bounces off of them and enters your eye through your cornea and lens. When everything is working perfectly, the cornea and lens work together to bend the light so that it forms a focused picture on the retina at the back of your eye.
As your eye shifts attention between near and distant objects, the lens of your eye changes shape to re-focus the picture on your retina. When it is relaxed, the lens is the right shape to focus on distant objects. When the eye is focused on a near object, the muscles of the eye push on the lens to change its shape so that a clear picture of the near object is formed on the retina.
Sometimes, however, the parts of the eye aren’t quite the right shape or don’t work together perfectly, which can cause images of near or distant objects or both to appear blurred-we call these refractive errors. Nearsightedness, farsightedness, astigmatism and presbyopia are all types of refractive errors.
Another common vision problem, cataracts, actually affects the lens of the eye. Contrary to popular belief, cataracts are not a cloudy film that forms over the eye. A cataract is simply a clouding of the natural lens of the eye-over time, the lens itself becomes more and more cloudy and discolored.
The good news is that modern techniques make it possible to correct many vision problems permanently-so you can see clearly, often even without glasses or contact lenses.
If you are under the age of 40 and are nearsighted, farsighted or have an astigmatism, LASIK surgery may be able to give you clearer vision-freeing you from glasses or contacts.
If you are over 40, presbyopia surgery may be able to restore your vision and even correct nearsightedness, farsightedness and astigmatism, as well-giving you clearer vision, often without the need for glasses or contacts.
If you are over 60, cataract surgery may be the best solution to help you see clearly. New cataract treatments can correct refractive errors like nearsightedness, farsightedness, astigmatism and presbyopia at the same time as your cataracts-often restoring clearer vision without the need for glasses or contacts.
Not sure what a particular term means? Click on words in bold to pull up the glossary tab.
Clear, curved surface at the front of the eye through which light enters the eye. Along with the sclera (the white part of the eye), provides external protection for the eye. Often called the window of the eye. During many types of vision correction surgery, such as LASIK, the cornea is reshaped to reduce or eliminate the main types of refractive error - nearsightedness, farsightedness and astigmatism.
The transparent disc behind the pupil that brings light into focus on the retina. As the eye ages, the lens often becomes cloudy and is called a cataract.
Irregularities in the cornea, lens or shape of the eye that prevent correct focus at any distance.
Transmitter at the back of the eye that contains blood vessels and nerves and sends images to your brain through the optic nerves.