Vision Problems

Lexington Eye Associates - Correcting Vision in the Boston Area with Offices in Lexington and Concord

Serving the Boston area from offices in Lexington and Concord, our refractive surgery and ophthalmology practice is dedicated to improving vision as well as educating our patients so that they can make informed decisions about their eye care. Below you will find a list of four common focusing and refractive vision problems and how they affect your eyes.

How the eye functions

In a normal eye, the cornea and the lens both focus light rays precisely onto the retina. The retina converts light to electrical signals, which are carried by the optic nerve to the brain. The visual portions of the brain then interpret these nerve impulses, resulting in sight. There are four focusing or refractive errors: nearsightedness (myopia), farsightedness (hyperopia), astigmatism, and presbyopia.

Myopia or Nearsightedness

Myopia occurs when the cornea is too steep or the eye is too long. When focusing on an object in the distance, light is focused in front of the retina, resulting in blurry vision. As the object is moved closer, the vision becomes clearer, since the light is focused on the retina.

Hyperopia or Farsightedness

Hyperopia occurs because the cornea is too flat or the eye is too short. Light rays are focused behind the retina, resulting in blurry vision. As the object is moved closer, the blur increases since the light is focused even further behind the retina.

Astigmatism

Astigmatism typically results when the cornea is steeper in one direction and flatter in the opposite direction (like the side of a football) rather than spherical (like a basketball). This causes light rays to be focused in more than one point, and may cause blurry or distorted vision at all distances. Astigmatism may occur alone or in combination with myopia or hyperopia.

Presbyopia and Monovision

Presbyopia refers to the natural loss of near vision. It typically occurs after age 40, requiring the use of reading glasses or bifocals. Presbyopia is caused by the loss of lens elasticity, which is required to focus on nearby objects. The lens actually loses flexibility throughout life, but this only becomes clinically apparent at approximately age 40.

There is currently no specific medical or surgical treatment for presbyopia. Patients over the age of 40 who have undergone laser vision correction have a choice. If both eyes are corrected to see well in the distance, then glasses will be needed for close-up work. Alternatively, if "monovision" is elected, one eye is corrected to see distant objects, while the other eye is corrected to see nearby objects. Monovision represents a compromise that allows for some preservation of near vision without the use of glasses.

If you are interested in LASIK in the Boston area, visit Lexington Eye Associates at our Lexington and Concord offices.