For some, it is a fad. Wearing glasses with designer rims look cool, accentuate your sense of fashion and whatnot. For others, it is necessity.

And, yes, for the latter category, this necessity is often at odds with the size of the bank account or wallet, hence the need for something ready and cheaper such as off the shelf spectacles, known in the ophthalmology speak as ‘ready-readers’– those cheap glasses that you can buy over the counter.

Whatever the reason, most people are known to buy reading glasses from supermarkets and pharmacies, eschewing opticians altogether, but such an action could lead to many harmful eye conditions.

The fashionistas aside, it is not uncommon to find people with genuine need of spectacles for reading hitting the counters to self-prescribe with ‘ready-readers’ and use it as an excuse not to have an eye test.

However, you would need a really active god watching over you to pick a fitting ready-reader lens for your eye condition. Often times, one will pick a stronger lens than they need; which is like taking more painkiller than is required.

"People who buy the wrong specs are risking headaches, eye strain and even eye damage,” says Dr John Nkurikiye, a consultant ophthalmologist at Dr Agarwal Eye Hospital in Kigali. "Some glasses bought off-the-shelf don’t have a UV (ultra violet) filter, and even those got from the optician are not guaranteed to have the UV filter, therefore, it’s safe to check out the glasses from a UV meter before wearing them.”

For the sunglasses, Dr Nkurikiye explains that the pupil contracts when one is in the light, whereas in the dark, it dilates. So when one wears sunglasses, the pupil is tricked with the shade into opening up resulting into the UV light penetrating the eyes. This means that while it is okay to buy sunglasses off-the-shelf, there is still need to buy them from an optician to ensure that they are coated with UV filter.

For ready-reader glasses, Aine Higgins, an Irish optician, in an article in Mayo News, says the function of the lens is to magnify.

"People think if the lenses magnify more, they are getting a better-quality set of spectacles, but that is not true. Not everybody requires the same amount of magnification. Off-the-shelf spectacles may allow you to read certain text size, but that does not mean they are the correct strength for you,” Higgins says.

"It is important that the reading correction be balanced for both eyes, and that the magnification is exact. The wrong lenses can cause eyestrain and accelerated deterioration. There are also many problems, such as astigmatism, that ready-readers cannot treat.”

The essence of eye checkup

Dr J. Praveen, an ophthalmic technician at Eye Care Optical in Remera, Kigali, says one cannot know the kind of disease they have if they just buy specs off-the-shelf. He advises that one should go through an optician for the necessary procedures and finally a proper prescription from a specialist eye doctor.

Dr Praveen says someone with a normal vision cannot wear glasses except those with plane lenses (glasses with zero power).

According to Dr Yuvaraj Vaiyali, a senior marketing executive at Dr Agarwal Eye Hospital, it is normal for anyone to experience some reduction of vision, which is caused by the lenses in our eyes losing elasticity (presbyopia).

It is, therefore, advisable to get your eyes tested by an optician every two years if you are in your 20s and over. Those aged 50 and above need annual eye checkup.

Online research by this paper unearthed several warnings by specialists to people who go for ready-readers.

One of the findings highlighted a scenario where an optometrist was asked to check the quality and prescription of 14 pairs of ready-readers from seven high-street stores and claimed to have found problems with half of them.

Higher-prescription glasses were found to have the most serious flaws, and readers were warned that the glasses "could cause eye strain, blurred vision, headaches or double vision.”

This means that the risks associated with the use of ready-readers transcend the more than the scary eye defects as the simplest of the problems usually are the kind that give rise to serious complications. For instance, buying ready-readers may mean that the wearer feels that they do not need to have a proper sight test.”

Opticians say only sight tests can provide a good health check of our eyes and can even detect certain conditions, including fatal ones, such as brain tumours.

Indeed, those tempted by a cheap, quick fix should always be wary that ready-readers may save you a few quid in the short term, but they could ultimately cost you your eyesight.