Presbyopia

Presbyopia is the condition that most people first notice around the ages of 40 to 45 years. Close tasks become difficult, especially in poor light. A common example is holding the newspaper or telephone book further and further away from you to make the print clearer, or having difficulty in threading a needle.

Presbyopia is not a disease - everyone experiences the aging process which causes presbyopia. It can not be prevented. It does not represent a threat to your eye's overall health.

Presbyopia is caused by the lens of the eye losing its flexibility as we age. Normally a person's eyes are focussed for distance vision. When you focus on close objects a muscle inside the eye changes the shape of the lens of the eye which, in turn, bends the light entering your eye to focus sharply on the retina. This is a process called accommodation. With age the lens is less able to change its shape and thus focusing on close objects becomes more difficult.

The changes in the flexibility of the lens is a gradual aging process that begins in childhood. However, its effect is first noticed around 40-45 years of age and increases between 45-65 years of age making close work or reading increasingly difficult.

Presbyopia is corrected by the wearing of a correct pair of glasses. An individual's prescription is designed especially for that person's close vision tasks. It will make distant objects blurry, so the glasses are only used for close tasks.

For convenience, sometimes bifocals, trifocals or progressive lenses can be prescribed. This means that a prescription for distance vision is incorporated in the top half of the spectacles and closer vision in the lower half of the spectacles. Another type of glasses used for presbyopia are look overs in which a lens is only provided for the lower half of the spectacle.

Between 45-65 years of age the strength of the glasses needed to correct presbyopia is likely to change significantly. Therefore it is recommended to have your prescription checked regularly - every two to three years, or if vision difficulties occur between these appointments.