Refraction Test

Contact lenses are booming in popularity. New advances in technology mean people who could not previously wear lenses can now spurn their spectacles in favour of contacts. And scientists are even promising lenses that could be worn for up to two years before needing to be replaced.

How can I tell if I need contact lenses?

modern-way-1Before you can tell if you are right for contacts, you need to have your eyes tested by a properly qualified optician – also known as an optometrist.


Optometrists who have qualified as contact lens specialists will have the initials DCLP after their name, standing for a Diploma in Contact Lens Practice.

In addition to testing the strength of your eyes – the common test where you read letters from a chart – the eye examination will determine the health of your eyes and your eyelids, and the quality of your tears, essential for lubricating the surface of your eye.

The curvature – the way the eye ‘bends’ – and diameter of the cornea at the front of your eye will also be measured, along with the size of your pupils and the position of your eyelids.

Using all this information, the optician will then make a decision about the most suitable lenses for your needs.

Whatever lenses you are given, experts recommend having an eye test every year to make sure you are still wearing the right strength for your needs.

Refraction Test


Hard Contact Lenses

The most old-fashioned lenses are hard contact lenses made from perspex. Although they last for a long time, oxygen cannot pass through them to reach the eye so users can only wear them for a short period of time. Hard lenses have now largely been replaced with rigid gas permeable lenses.

Extended Wear Lenses

The final option available is extended wear lenses. Although most contact lenses are worn on a daily basis i.e. you take them out at the end of the day, some lenses allow you to sleep in them. These extended wear lenses can be worn for up to one month before you need to take them out and clean them or dispose of them.

Disposable Lenses

The latest development in contact lenses is disposable lenses. These are soft lenses that come sealed in their own sterile containers, virtually eliminating the need for a cleansing and sterilising routine. Disposable lenses can be worn on a weekly or monthly basis, so you throw them away at the end of this period, or even on a daily basis. This means you open a fresh pack every day.

Rigid Gas Permeable Lenses

Rigid gas permeable lenses are made from a plastic-like material, but have tiny holes in to allow oxygen to pass through to the eye. They may be more suitable for someone with a high degree of astigmatism – an irregularly shaped cornea – as they can correct more serious problems. Soft contact lenses are the most popular type of contact lenses. They are made from a gel-like plastic that have a high water content. They easily allow oxygen to reach the eye and because they are so supple, can mould easily to the shape of the eyeball. Because the lenses have a high water content, they also tend to be larger and thinner than gas permeable lenses.