These are required when two different prescriptions are necessary: one for distance, the other for reading. It is common to need different strengths for different tasks from approximately the age of 45. This common condition which affects everyone, is known as Presbyopia.
Just like multifocal spectacles, multifocal contacts incorporate different strengths within different parts of the lens. Some have reading segments that resemble bifocal lenses. Others have ‘rings of alternating power’.
Multifocal technology is constantly advancing and there is now a range of manufacturers offering lenses in different designs. The success of these lenses depends on factors including:
- the prescription
- the shape of the eyes
- visual demands
Some people get extremely good vision, while others find that they sometimes have to use additional glasses for certain tasks. There is a small but significant percentage of people who do not get on with them at all and prefer to wear ordinary contact lenses to correct general vision, and then wear glasses on top just for reading.
This is an alternative option to multifocals. In monovision normal lenses are worn, but the power is modified so that one eye is corrected for distance viewing and the other for reading. Although it sounds strange it works very well, especially for those under 55 and has very high success rates.