Question

Explain presbyopia in detail with diagram.

Answer 1

Presbyopia is the medical name for age-related long-sightedness. It is a normal part of ageing, and not a disease. Presbyopia is a type of sight problem called a refractive error. Refraction refers to the bending of light. In terms of the eye. A refractive error means that the eye cannot focus light on to the retina properly. This usually occurs either due to abnormalities in the shape of the eyeball, or because age has affected the workings of the focusing parts of the eye. In order to see close-up objects, our eyes have to accommodate. This means that the lens changes its thickness.
It can do this because of the ciliary muscles that attach to the suspensory ligaments at either end. As these muscles tighten, the lens becomes more thickened and curved, and the light rays from close objects are brought into sharp focus on the retina.
The lens of the eye becomes more stiff, and less elastic as we get older.
This makes it more difficult for the lens to change shape.
With the lens in its normal resting position you are still able to focus on objects in the distance - long sight.
Cause
1. Age
2. UV light exposure
3. Had close up work

Symptoms
1.Tiring of the eye
2.Blurred vision

Treatment
1. Use of glasses
2.Contact lens
3. Surgery