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But cheap spectacles are suitable for people with only presbyopia and no other eye problems, say experts
Apair of prescribed lens reading glasses could set you back a couple of hundred dollars. Or you could get a $2 pair of reading glasses from a pasar malam stall.
But can anyone use the cheap version?
It is a cheap and effective way for people who need reading glasses, said Dr Leonard Ang, the medical director of The Eye and Cornea Transplant Centre.
However, they are suitable for those with only presbyopia and no other refractive eye problems, he stressed.
Presbyopia is a natural age-related process in which the lens of the eye weakens and becomes unable to focus on near objects. This usually starts from the age of 40.
Existing conditions contributed by a person’s genes and the environment – such as myopia (short-sightedness), hyperopia (long-sightedness) or astigmatism – may render these generic glasses unsuitable for such wearers.
People with conditions like myopia or astigmatism may have power differences between each eye – something that generic spectacles cannot address, said Dr Julian Theng, a presbyopia specialist at Eagle Eye Centre.
Presbyopia, by itself, usually affects both eyes symmetrically.
Each person’s eyes are also set apart at different distances. Because of this, the lens centre of these glasses may not properly align to the centre of the eye’s lens, causing distortion, said Dr Theng.
So prescription lenses from an optician are always best. The cheaper glasses would be an alternative for presbyopia cases with no complications, as long as the user feels comfortable wearing them.
They come in standard degree increments from 50 to 300 and people can just try them on to see which power suits them best for reading, said Dr Ang.
Would these glasses worsen your eyesight? Unlikely, say doctors, even if they do not exactly match your needs.
“You may encounter giddiness or discomfort but there won’t be permanent damage,” said Dr Theng.
However, you may need to change your glasses regularly as your presbyopic degree increases by about 50 degrees every five years, he added.
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