When you visit the Optician, they’ll start by asking some general questions as to your health, whether you have any problems with your sight and questions also about your family’s ocular health history.

They will then carry out a number of tests using test charts, which enable them to assess your distance vision.  And then by using a Snellen Near Point chart, they can test your near vision.  These tests give an accurate measure of your eyes ability to see text and objects clearly at various distances.

He or she will then examine your eyes with a microscope to check the internal and external structures of your eyes.  Eye diseases such as cataracts, glaucoma and macular degeneration can be detected as well as any retinal abnormalities that may be a sign of other underlying conditions.

The optician may also give you an eye pressure check or a visual field examination to test for any blind spots in your peripheral vision.  The range of movement of your eyes will also be assessed to determine that your eye muscles are in working order. And your colour vision may also be tested using specially designed colour vision plates.

If your eyesight needs some correction, the optician will then go through potential remedies and aid you in making the decision that is right for you and your eyes.

And if you need corrective eyewear (glasses or contact lenses), opticians will use a variety of equipment to ensure a correct fit.  These include:

• A lensometer – to verify the correct prescription in a pair of eyeglasses, to properly orient and mark uncut lenses, and to confirm the correct mounting of lenses in spectacle frames.
• A pupilometer – to measure pupillary distance to ensure any glasses are centred in the visual axis.

Things to look out for at the opticians:

• Cabinet of glasses
• Eye charts
• Testing glasses
• Lensometers
• Pupilometers

> Visit Professor Hallux’s Map of Medicine homepage

Images courtesy of the Wellcome Trust