Complete Spectacles by Eye Experts
- Fashionable prescription spectacles at discount prices, including rimless, semi-rimless and bifocals. Prices start at £15.

The Spectacle Prescription Explained

SPH
SPH (Sphere) is measured in "diopters" and shows how long or short sighted you are. If you are long sighted, the number in the sphere column will have a plus "+" before it. Conversely, if you are short sighted, the number will have a minus "-" before it.

CYL
CYL (Cylinder) is a measure of the amount of astigmatism (distortion) that needs to be corrected for.

AXIS
AXIS gives the direction of the astigmatism and is measured in degrees.

PRISM
PRISM corrections are sometimes needed to balance the eyes so that you use them both together.

INT
INT (intermediate) is a measure of the correction needed to see at intermediate distances, such as when working at a computer terminal. You can either have a separate set of prescription glasses for this purpose, or alternatively have a prescription for varifocal lenses that will work at all distances.

Eye conditions, a few questions and answers

What is Presbyopia?

Presbyopia is a condition that starts in your forties and ultimately affects everyone. Its symptoms are blurred vision when reading or doing other close work, where previously there was no such blurring. This is caused by a loss of elasticity in the muscles that operate the lens in the eye, which is a natural part of the aging process. It is typically characterised by people with normal vision having to hold newspapers at arm's length in order to be able to read them. Presbyopia can be corrected with bifocals, varifocals or reading glasses alone.

Could laser treatment help me?

There are three types of laser treatment available in the UK - Lasik, Lasek and PRK. They all use a laser to cut the cornea to reshape it, and are most successful if you are mildly short sighted with a stable prescription, although long sight and astigmatism can also be treated. As with all surgical procedures, there are risks although it works well in the majority of cases. If you are considering this form of treatment, you will need to be individually assessed and have the risks explained to you.

It is worth bearing in mind that your eye prescription will likely change as you get older. My prescription has now changed from the one on the top left of the page - I now have a prescription of -1.75 in both eyes. My previous prescription was stable for the past 15 years, but now I have reached my mid forties it is starting to change. Had I had laser eye treatment, I would now have to wear reading glasses. As it is, my eyesight is improving and now I'm optimistic that it might improve so much that I will no longer need a corrective prescription. Watch this space...

How good does my eyesight need to be for me to drive legally in the UK?

You need to be able to read an old style UK number plate from 20.5m and a new style UK number plate from 20m in good daylight - if you need prescription glasses in order to do this then you will need to wear them whenever you drive.

In addition, other eye conditions that can affect your ability to see need to be reported to the DVLA. These include cataracts, glaucoma, diplopia (double vision), some forms of diabetic retinopathy and other conditions. The actual guidelines used by doctors are available at the DVLA web site.