How often should you have an eye test?

The NHS advice for adults is to have your eyes tested every 2 years, or more often if your ophthalmic practitioner or optometrist tells you to. That is a general interval for people with no particular eye condition and no new symptoms. It is not a rule that everything is fine in between.

The reasoning, given on the NHS website, is that your eyes rarely hurt when something is wrong. Conditions such as cataracts, glaucoma and macular degeneration are ones that optometrists are trained to detect, so a routine test is meant to find potentially harmful changes before you would otherwise notice them.

The NHS explains that at an eye test you are examined by an ophthalmic practitioner or optometrist who is trained to recognise abnormalities and conditions such as cataracts or glaucoma. Optometrists examine the internal and external structure of the eyes to detect conditions such as glaucoma, macular degeneration and cataracts, and may test your ability to focus, coordinate your eyes and see depth and colours accurately.

It is therefore more than a check on whether you need glasses. After the test you are legally entitled to your optical prescription or a statement that you have been referred for further tests. Whether or not you buy glasses is your decision, and the NHS says you should never feel obliged to buy glasses from the place where you had your test.

The 2-year interval is a baseline. The NHS says you may be advised to come more often by your practitioner, and that if you are concerned about your sight before your next test is due you should visit your ophthalmic practitioner or optometrist. They can carry out an NHS sight test earlier than planned if it is clinically necessary. Examples of reasons people ask for an earlier test include:

• You notice a change in your vision, such as blurring that does not clear, or difficulty with distance or reading.

• You have an eye condition, or a practitioner has recommended a shorter interval.

• You have a health condition or a family history that your optometrist has said needs closer watching.

• Your glasses no longer seem right for you.

A sudden loss or change of vision, new flashes or floaters with a curtain over part of your sight, or severe eye pain are not situations for waiting for the next routine test. These need urgent assessment through an emergency eye service, an urgent GP or optometry appointment, NHS 111 or A&E, depending on what is available locally. The related pages linked below describe warning signs for specific conditions.

Eligibility for a free NHS test and the timing of the next one are linked. The NHS says that if you are eligible, you can have a free test every 2 years, and possibly more often if your practitioner recommends it. If you want a test more often than your practitioner considers clinically necessary, you will have to pay for a private test. A test paid for privately resets the clock: you will not be eligible for a free NHS test until your next one is due, usually 2 years later but sometimes sooner, and the person testing your sight can advise.

It helps to bring your current glasses, a list of your medicines and details of any eye conditions in your family. After the test, keep your prescription, since you are entitled to it and can use it to compare prices. If you are under 16, 60 or over, have diabetes or glaucoma or meet other criteria, you may be entitled to a free NHS test, which is covered in the eligibility guide linked below.