Eye glasses or lenses are crucial for correcting vision problems that may otherwise deprive one of living a normal, productive life.

However, the correction is only guaranteed if the eye glasses are kept in good condition, or replaced in time when necessary.

Many of us will go for years without considering replacing eye glasses because there is no "shouting” evidence that they are losing effectiveness.

But medics warn that, if not replaced in good time, it might cause one unnecessary eye strain and exhaustion. Blurred vision, headaches and neck aches, are just some of the warning signs that the glasses are becoming faulty and in need of replacement. Technology trends

Just like phone technology, technology behind the making of eye lenses keeps revolving just to give users a better experience. These days lenses are customised to suit the job one does.

"For instance, if you are the kind that spends a lot of time before a hand-held screen or computer, chances are that your doctor will prescribe a lens that minimises eye strain,” says Innocent Habimana, an ophthalmic technician working with Vision For a Nation Foundation, a local charity organisation that offers free eye care services.

Quite similarly, medics say one should try to remember how clear their vision was after they had just acquired current lenses. If, for instance, they can no longer watch television clearly from what is a relatively normal distance, then they should know that their glasses are starting to get faulty and, therefore, seek help from an ophthalmologist.

Growth of refractive errors

Habimana notes that refractive errors grow (worsen) even for those with glasses, which can only be countered with stronger lens.

Also, over time, one’s glasses may develop wear and tear on lenses or important moving parts, sometimes without the notice of the user. So, it is crucial to take them to ones doctor for fault inspection periodically, medics advise.

"If you are the kind that looks at someone or something like a billboard with one or both eyes partly closed in an attempt to see more clearly even with lenses on, sometimes it is an indication that your glasses need replacement,” says Pacifique Uwamahoro, an ophthalmic clinical officer.

Uwamahoro says that some people, especially young ones, just opt for fashionable frame replacements so as to match with the trends.

Eye exams

Eye glasses should be replaced when your optometrist recommends that they should be. This usually will occur in tandem with your regular eye exam.

The American Optometric Association recommends that non-senior adults and children over age six have regular eye exams, a minimum of once every two years if they do not have risk factors for poor vision.

Seniors over age 60 and individuals with risk factors should have an eye exam every year, or more frequently if recommended by their doctor.

During this regular eye exam, you will need to ask your optometrist whether or not you need to replace your glasses with a new pair. Be sure to bring your old glasses with you so that your eye doctor can inspect them for flaws and durability.

"Regularly wipe your glasses with a clean piece of cloth before keeping them away in a protective case to minimise chances of damage when not in use,” advises Joseph Majyambere, an ophthalmic nurse attached to Ndego Health Centre, Kayonza District, Eastern Province.