Cataracts
Description: A pathological condition in which the lens becomes cloudy preventing “a clear image from forming on the retina” (Cassin p.59).
Part Affected: Lens
Functional Implications & Effects on Visual System:
Cataracts can affect your vision in the following ways:
· sensitivity to light and glare (which may make driving difficult) (Health Encyclopedia)
· less vivid perception of color
· cloudy, fuzzy, or foggy vision
· frequent changes to your eyeglasses prescription may be necessary
· double vision in one eye
· near vision may improve for a short time. This temporary improvement is called second sight (WebMD)
NOTE: Some cataracts do not cause vision problems (WEBMD).
Treatments: Surgery is the only way to correct vision loss caused by cataracts. But cataracts in older adults do not always need to be removed. The vision loss from a cataract often happens slowly and may never become severe (WebMD). Two types of cataract surgery most often performed are equally effective in restoring vision. These are:
Extracapsular surgery, in which the lens is removed and the back half of the capsule behind the lens (the posterior capsule) remains in the eye
Photoemulsification, a type of extracapsular surgery in which the lens is softened with sound waves and removed through a needle. The posterior capsule remains (Health Encyclopedia).
Stability of Condition: The condition can be congenital, caused by disease or by trauma to the eye, but is usually due to age. These are called senile cataracts and are the most common type. (Health Encyclopedia). With Cataracts there is also the possibility that Glaucoma could develop (Lueck p.476).
Cataracts are typically detected through a medical eye examination. The usual test for visual acuity (the letter eye chart) may not reflect the true nature of visual loss. Other tests that measure glare sensitivity, contrast sensitivity, night vision, color vision, and side or central vision help to nail down the diagnosis (Health Encyclopedia).
This photograph shows a cloudy white lens (cataract) over the pupil. Cataracts are a leading cause of decreased vision in older adults, but children may have congenital cataracts. With surgery, the cataract can be removed, a new lens implanted, and the person can usually return home the same day (Medline Plus (2008).
References:
1. Health Encyclopedia: Diseases and Conditions. Retrieved June 25, 2009 from web site: http://www.healthscout.com/ency/68/114/main.html
2. Goldberg, Stephen M.D. (1993) Ophthalmology Made Ridiculously Simple. (10th Printing) Miami, Florida: MedMaster, Inc.
3. Cassin, Barbara & Solomon, Sheila A.B. (1997). Dictionary of Eye Terminology. (Third Edition) Gainesville, Florida: Triad Publishing Company.
4. Lueck. Amanda H. (2004). Functional Vision: A Practitioner’s Guide to Evaluation and Intervention. New York: American Foundation for the Blind Press.
5. WebMD. Retrieved June 25, 2009 from web site: http://www.webmd.com/eye-health/cataracts
6. Medline Plus (2008) Medical Encyclopedia Retrieved June 26, 2009 from web site: http://www.nlm.nih.gov/medlineplus/ency