If you have already read part one of our guide to understanding your glasses prescription then you’ll love this second installment, helping you to decifer what your glasses prescription really means.

So what else might you find written on your glasses prescription?

When handed your prescription, it will usually be written on a headed piece of paper from the optician or, if you are of a certain maturity, an NHS form (with GOS2 written in the corner). The prescription is obviously the most important part of the form but there are sometimes, if not always, other bits of information scribbled alongside that can get overlooked or confused with the actual prescription itself. So here are our top tips for what to spot.

1. Check it has your correct personal information

A sight test form must have your name and the date on which your sight test was carried out on it. A prescription without a date is not complete. Any ophthalmologist worth his parking space will also put your date of birth on it and the date your next eye test is due. Your age is a good indication to an optician of how susceptible you might be to certain eye conditions such as glaucoma, age related macula degeneration, diabetes and high blood pressure; this is why your date of birth is a very useful thing to have on your prescription.

2. Understand your Vision and Visual Acuity readings

These two, although sounding similar, are kind of like the ‘before and after’ results of the test. When you sit in the ‘mastermind’ chair and desperately start trying to read all the letters on the chart don’t get flash and try to remember them from the last time you were there, the optician will find you out! The point is that the letters on the chart represent how well you can see (or not) without your glasses on. The results of your chart test will give you your uncorrected ‘vision’ reading; it is normally written as a fraction like 6/18. There will be one for each eye (monocular) and one for both together (binocular).

After your eye test, your optician will now get you to put on a trial frame and ask you to repeat the letter reading as far as you can go whilst they drop in lenses to find your best prescription. Much like tuning into a radio station it’s not just a question of ‘cranking up the power’ but more a case of finding the comfortable level of vision for you. Again he or she will test each eye in turn and then both together. This corrected vision is called the Visual Acuity and is important because it lets us know how well you see with your specs on. Sometimes 20/20 vision is not achievable no matter how many lenses are put in front of your eyes. This measurement is written as a fraction and if good visual acuity is achieved may look like 6/4 (i.e. vision better than 6/6).

3. Understand your Reading Addition measurement

The ADD or addition is your requirement for reading and is normally worked out for a distance of around 12-14 inches. If you work at a different distance (like a stamp collector for example) you should let your optician know this. The ADD is closely linked to age and normally manifests itself from the age of 40. As your eyesight will worsen with age, at 40 your reading addition will be approximately +1.00, +2.00 at 50 and +3.00 at 60 and so on. So there’s no way you can lie about your age to us opticians!

We hope you found these tips useful. As always; if you have any questions about your prescription, you can contact our team of dispensing opticians on 08456 88 20 20, Monday-Friday 8am-6pm and Saturday 10am-4pm.