Eye tests

For most people, it's advisable to have an eye test every two years, but it's best to attend earlier if any eye problems occur or if advised by your optometrist.

Yes. A comprehensive sight test includes checking the health of the inner and outer parts of the eye.

Even if you're happy with your vision it's worth having a regular check‑up. Eyes can be affected by a number of conditions which may be picked up early through a sight test, giving it less chance of affecting your vision.

You should have an eye examination every two years or more regularly if advised by your optometrist.

It depends on the patient, but a young, healthy person with no apparent problems should take around 20 minutes.

Someone older, perhaps with high blood pressure, diabetes, glaucoma or other ailments can take much longer.

Your optometrist will determine what clinical tests are needed to provide the correct information for new spectacles or contact lenses; if necessary, they might refer the patient for a medical opinion.

Sight tests, also known as eye examinations, are more than just tests of your vision.

A comprehensive sight test includes a thorough examination of the front and back of the eye for any health problems, too.

You might have certain tests ‑ such as 'auto‑refraction' (to provide the optometrist with a rough estimate of any spectacle prescription) and 'tonometry' (a measurement of the pressure inside the eye) before entering the consulting room.

The optometrist will ask you questions about any problems you're having with your eyes or might have had in the past, and about any family history of eye problems (some eye problems can be hereditary).

The vision test (known as the 'refraction') includes the use of a letter chart, with different lenses being placed in front of the eye while the optometrist uses further techniques to fine‑tune the prescription.

The prescription is the power of lens for the right and left eye which will correct the patient's vision. During the eye test the optometrist checks the condition of the eye's various structures using an opthalmoscope and a number of other instruments such as a slit‑lamp and a visual field analyser.