Common Conditions
Most vision problems occur because of an error in how our eyes refract or bend light to produce an image on the retina. Once diagnosed, these disorders are commonly treated with prescription lens correction -- either eyeglasses or contact lenses.
Emmetropia or Optimal Focus
Emmetropia is not a refractive disorder. It is the term used to describe when a distant object is focused correctly on the back part of the eye. The objective of vision correction through prescription lenses is to achieve this state.
Myopia or "Near sighted"
You will be diagnosed as near sighted if distant objects focus in front of the retina, so that you only see near objects clearly. If uncorrected, you may find yourself squinting, suffering blurred vision, eye strain or headaches.
Hyperopia or "Far sighted"
You will be diagnosed as far sighted if close objects focus behind the retina, so that while distant objects may be clear, you may have to hold a newspaper at arm's length in order to see it clearly. Hyperopia is often not self-detected because it does not always cause blurry vision. However, uncorrected, it can show up as poor concentration, reading difficulty, tired or red and crusted eyes, or headaches.
Astigmatism
Astigmatism means "without a single focal point." Ideally, the curve of the front of the eye (the cornea) is round or spherical. If the shape is more like an egg or football, where the curvature is flatter in one direction than the other, no sharp focus occurs. Uncorrected, astigmatism can cause blurred vision, squinting, headaches, head tilt, red eyelids and light sensitivity.
Presbyopia
Presbyopia is a normal condition of aging - usually associated with the need for bifocals. As we get older, the lens of the eye loses its elasticity, so that the eye's ability to focus quickly from distant to near objects decreases, particularly in poor light situations. The earliest signal of the onset of presbyopia usually occurs after age 40 as a tendency to hold reading material at arm's length.
Muscle Imbalance
When the muscles controlling eye movement do not work evenly, poor eye coordination may result. Symptoms include headaches, seeing double, occasional blurred vision and poor posture. Special optometric testing and training procedures are required to treat this problem.
Crossed Eyes (Strabismus)
Crossed eyes occur when the eye muscles point one or both eyes in the wrong direction. This often first appears between birth and 21 months. Because the brain has difficulty in blending the two images, problems with depth perception and double vision may occur. Treatment for crossed eyes has excellent results if detected within the critical period of ages 6 months to 5 years, and may include glasses, prisms, vision therapy and, in some cases, surgery. Untreated, the condition may get worse and result in a lazy eye.
Lazy Eye (Amblyopia)
Lazy eye is the loss or lack of development of vision in one eye. This may be as a result of a large difference in the degree of refractive error between the two eyes or, if eyes are crossed, only one eye's image is fully processed. This is a developmental disorder, usually occurring well before the age of five. Essentially, the child ignores the weak eye, using only the strong one. While, untreated, the vision of the eye itself will not get worse, the condition will progress until the eye becomes virtually unused. Since it is very difficult to correct amblyopia at that point, early detection and treatment are extremely important.
Corrective lenses, prisms, contact lenses and/or vision therapy are often used to treat amblyopia. In less developed cases, patching the good eye often stimulates and strengthens the weaker eye.
