Presbyopia is a condition where the eye gradually loses the ability to focus at a normal reading distance. It is usually first noticed between the ages of 40 and 50 years when people find that they can no longer focus comfortably on objects closer than at arm’s length. Presbyopia is not a disease and it affects everyone. Presbyopia is usually corrected by reading glasses (which will make near objects clear but distant objects blurry) or multifocal glasses (which incorporate progressive lenses that provide clear vision at both distance and near).
However, presbyopia can also be managed by prescription of contact lenses. The most common form of contact lens correction for presbyopia is monovision in which one eye is corrected for distance and the other eye is corrected for near. There is better than an 80% success rate with this mode of correction with the main disadvantage being a slight reduction in depth perception. Some monovision patients often require 3 contact lenses - 2 distance and 1 near - whereby they can alternate between a distance and a near contact lens in one eye, while always using a distance contact lens in the other eye. This way they can be binocular for sporting and recreational tasks while retaining the use of monovision for work and social occasions.
There are also multifocal contact lenses that attempt to correct distance and near vision with the same lens. Disposable soft multifocal contact lenses utilize the simultaneous vision principle, whereby the distance and near zones of the lens are positioned over the pupil continuously. The major problems with this type of design are patient adaptation and loss of contrast, both as a result of the simultaneous presentation of the distance and near images. Despite this, the success rate with disposable soft multifocal contact lenses is also quite high and there are now even daily disposable multifocal lenses available – which I love wearing given that I am ageing rapidly! – that offer great convenience and excellent vision at both distance and near.