PRESBYOPIA

Presbyopia is a condition that comes with age and manifests by progressive inability to focus on close objects. It starts to develop usually after 40 years of age and can be mixed with farsightedness (hypermetropia), but the cause is different..

When people develop presbyopia, they find they need to hold books, magazines, newspapers, menus and other reading materials at arm's length in order to focus properly. When they perform near work, such as embroidery or handwriting, they may have headaches or eyestrain, or feel fatigued.

The first symptom of presbyopia is usually the momentary blurring of distant objects that occurs after doing close work. For example, if a man is reading and then looks up and across the room at his wife, her image is blurry for a few moments. This occurs because the crystalline lens can no longer rapidly change focus (accommodate) from near to far. As time goes on, it takes longer to refocus. Other symptoms include:

• Blurry vision of close objects
• Difficulty reading small print
• Eye fatigue, especially when reading in poor lighting or at the end of the day
• Eyestrain and headache when doing close work
• Holding reading material at arm’s length to see it clearly

Presbyopia is caused by an age-related process. This is different from Astigmatism, Nearsightedness and Farsightedness, which are related to the shape of the eyeball and caused by genetic factors, disease, or trauma. Presbyopia is a form of gradual loss of flexibility in the natural lens inside your eye.

Presbyopia develops over several years, as the lens capsule loses its ability to expand as a person ages. The result is that while distant objects are seen clearly, close objects are blurred because the lens cannot resume the shape that it needs to bring them into focus.

These age-related changes occur within the proteins in the lens, making the lens harder and less elastic with the years. Age-related changes also take place in the muscle fibers surrounding the lens. With less elasticity, the eye has a harder time focusing up close.