In middle to old age, usually from the early 40s to mid-50s, the internal lens of the eye begins to harden and cannot change its focus to see nearby objects.
This is a natural process which older adults will go through, called presbyopia. This is not to be confused with long-sightedness (which also causes near vision trouble but for reasons unrelated to the normal aging process).
Unfortunately we do not yet have a cure for presbyopia. Vision correction strategies include prescription glasses and contact lenses.
Those opting for glasses often get into the habit of leaving them on. Then they worry they are damaging their eyes from overuse of their reading glasses.
We often get asked if leaving your glasses on all the time damages your vision. The answer, in short, is no. This does not damage your vision.
Why then does it seem like your vision is getting worse? This is because presbyopia progresses. The internal lens in the eye continues to get harder and more inflexible as we age. This means the strength of reading glasses we need also increases over time. Eventually your long-distance vision can become affected too – usually if you were already long-sighted; or hyperopic.
Many people find that their reading glasses, once worn for close-up tasks only, are now being worn all the time, even for distance tasks such as driving.
With worsening eyesight, many people worry that the reading glasses have made their vision worse. This is not the case however, as in this age group, the eyesight is naturally worsening due to age, with or without the use of glasses.
You may find the reading glasses that you are habitually wearing all of the time are now no longer sufficient for near tasks. This can become irritating for you if you are using multiple pairs of glasses to suit different tasks.
Multifocal prescription glasses can help to provide a greater range of vision than reading glasses. Bifocal lenses allow clear vision in the distance and have a small segment towards the bottom of the lens which contains the prescription required for reading.
The more modern progressive prescription lenses have a gradual prescription change from the top to the bottom of the lens – allowing clear distance, along with intermediate and near vision prescriptions.
Occupational lenses have a more subtle prescription change from the top to the bottom of the lens allowing clear intermediate and near vision – a great option for those whose work is largely VDU (computer) based.