Alternative Names loss of accommodation of the lens of the eye
Definition Presbyopia is an eye condition in which the lens loses the ability to focus over time. It then becomes difficult to see small objects, especially close up. This condition usually begins in people starting at about age 45. Many people find that they need reading glasses or bifocals after this age.
What is going on in the body? Accommodation is the ability of the lens in the eye to adjust itself for focusing close up. The lens changes from a flat, thin state to a thicker, more curved state to allow a person to see a distant object versus a closer one. In individuals with presbyopia, the lens becomes less flexible.
What are the signs and symptoms of the condition? Symptoms of presbyopia include:
blurred vision, especially when viewing objects close up, less than 50 centimetres from the eye
tired eyes
a need for more light in order to read
inability to do tasks that need close-up focusing, such as threading a needle
What are the causes and risks of the condition? Normal ageing causes changes in the eye that lead to problems with focusing. Only in rare cases is this condition related to other factors. Trauma, and certain diseases, especially a contagious disease called diptheria (dip-thee-ree-ah, may weaken the muscles in the eye.
What can be done to prevent the condition? There is no known prevention for this condition.
How is the condition diagnosed? This condition is suspected when a person begins having trouble with near vision after age 45. An eye doctor confirms the diagnosis during an eye examination.
What are the long-term effects of the condition? Around age 45, people find that they may need glasses for distance or near vision. Often people in this age group will need separate glasses for distance and near vision. Unless a person has an eye disease, such as a cataract that causes clouding of the lens, or problems involving the retina, glasses usually correct farsightedness. Sometimes contact lenses or surgery make glasses unnecessary.
What are the treatments for the condition? Glasses, either reading glasses or bifocals, are the usual treatment. Today many people choose multifocal lenses, which work well. Since more than one lens prescription is usually needed for clear vision, contact lenses do not generally work for this condition. Bifocal contacts work well for some people.
How is the condition monitored? After age 45, most people will need eye examinations every 2 years. If another eye problem is involved, examinations are needed more often.
Author: William Stevens, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
