Presbyopia is a common condition that makes vision difficult at a normal reading distance. It is not a disease.
Close tasks such as reading and sewing become difficult, particularly in poor light. For example, you may find that you are holding your newspaper further away from your eyes to make the print clearer. You may also have difficulty concentrating when reading or you may find periods of close work result in sore eyes, headaches or tiredness.
It is important to understand how your eyes change their focus for viewing close objects. Normally they are focused for distance vision. To focus on close objects, a special muscle in the eye changes the shape of the lens. This process is called accommodation.
With age the human lens loses its flexibility and is less able to change its shape. This is a completely normal ageing change, just like stiffening joints or greying hair. The loss in lens flexibility is the reason that close focusing becomes more difficult.
Presbyopia is corrected by a prescription designed especially for close distances, in the form of spectacles, contact lenses or intra-ocular lenses.
Having different prescriptions in glasses for distance and reading can be a nuisance, especially if you have to change spectacles all the time. One way around the problem is the use of multifocal intraocular lenses. These are special implants that have a prescription for distance, intermediate and near vision in concentric rings throughout the lens. They will give you independence from glasses from most activities.