An eye test is a systematic examination of your eyes and your vision. It is carried out by an optician, optometrist or ophthalmologist, depending on the reason for and the depth of the examination. The aim is to determine how well you can see, whether you need glasses or contact lenses, and whether there are any signs of eye conditions or other health problems.
There are various types of eye examinations. A standard eye test at an optician’s focuses mainly on your visual acuity and refraction – in other words, whether you are short-sighted, long-sighted or have astigmatism. A more comprehensive examination by an optometrist or ophthalmologist can also measure the pressure inside your eye, examine your retina and optic nerve, and map your field of vision.
What is checked during an eye examination?
During an eye examination, various aspects may be covered:
- Visual acuity: how clearly you can see at different distances, often using a chart or a projection.
- Refraction: the measurement of your eyesight to determine whether you need corrective lenses and, if so, what strength.
- Intraocular pressure: the measurement of the pressure inside your eye, which is important for the early detection of glaucoma.
- Retina and optic nerve: examination of the back of your eye using a lamp or camera, to detect conditions such as macular degeneration or diabetic retinopathy.
- Field of vision: testing your peripheral vision to detect blind spots or loss of vision.
- Eye movements and coordination: how your eyes move and whether they work together properly.
- Anterior segment: examination of your cornea, iris, lens and tear film, for example using a slit lamp.
Who carries out an eye examination?
An optician can carry out a basic check of your visual acuity and refraction, and advise you on glasses or contact lenses. An optometrist has further training and can carry out more extensive tests, such as measuring eye pressure and examining the retina, and refer you to a specialist if anything is found to be amiss. An ophthalmologist is a medical specialist who makes diagnoses, prescribes treatments and performs surgical procedures.
How often is an eye test advisable?
How often you should have your eyes checked depends on your age, your health and your risk factors. As a general guideline, it is often recommended that you have your eyes checked every two years if you have no symptoms. If you wear glasses or contact lenses, or if you have an eye condition or are at increased risk, an annual check-up may be more appropriate. Your optician, optometrist or ophthalmologist can advise you on the frequency that is right for you.