Progressive glasses are used for the treatment for presbyopia or old age sight. Presbyopia occurs from the age of 40 years old and up.
Progressive glasses are designed to give the wearer both clear vision for distance as well as clear vision for varying distances of near vision.
Progressive glasses are however not recommended for everyone. They may be unwise in occupations which involve climbing or uneven surfaces and in the elderly who have recurrent falls.
The usual design of a progressive glasses lens is such that the upper portion of the lens is used for viewing distance. The lower portion of the lens has a central transition corridor of increasing power for near vision from top to bottom. The lowest portion is for near viewing. The portions of the lens to either side of the central corridor have been called ‘zones of confusion’.
There are many manufacturers of progressive lenses in the marketplace.
They are all to some extent governed by the same laws of physics.
Depending on the manufacturer and design, the progressive elements of the lens may be built into the front, back or both front and back of the progressive lens.
Astigmatism at the edges of the central transition corridor result in visual distubances. One way to minimise this might be to choose designs with more gradual transition zones. However, consumer information for such comparisons is lacking.
Choosing the appropriate height of the lens will also help optimise vision. Seek advice from your eye care professional.
Lastly, it may make some sense to start wearing progressives early when the near addition is low so that the transition to progressive glasses is easier. Some re-learning of daily tasks may be required e.g. the way we check the side mirrors when driving. Patience and persistence is required to get used to them.