28th July 2021
Eye testing is vital: as well as making sure you get the right glasses, it can help you identify serious health problems.
An eye examination is not just about getting new glasses. It’s a chance to spot potentially serious eye and health problems such as glaucoma and diabetes.
Opticians had to make some adjustments to routine eyecare, but more can be done remotely or online than you might think.
Telephone and video assessments, downloadable home eye charts and video appointments are some of the ways opticians have been assisting their patients during the pandemic.
A lot of these measures will stay in place as restrictions ease.
Face to face appointments will be different to how they were before the pandemic. Opticians must adhere to strict protocols on infection control and personal protection equipment (PPE).
When we asked opticians what patients can expect, many said that practices will not be able to fit in as many appointments during the day, due to hygiene and distancing requirements, so there may still be longer waits.
Even seemingly simple things like fitting glasses will require opticians to be in full PPE. There might also be some elements of eye tests that still can’t be done – for example, puff tests (which measure intraocular pressure to check for issues such as glaucoma) that produce aerosols and might increase the risk of infection.
Some practices might ask customers to wear masks or fill out a screening survey, so check before you attend.
We surveyed almost 5,000 Which? members about their experiences to find out which companies are rated best and worst for eye tests, including quality of customer service and thoroughness of tests.
Best places for eye testing
Vision Express (including Vision Express within Tesco)
Table notes: Table last updated July 2020. Based on a Which? survey of 4,749 Which? members in April/May 2020. Customer scores based on satisfaction with the store on last visit and likelihood of recommending to a friend.
It's difficult to judge whether you're getting a good consultation including the right tests, and if you're left feeling unsure, you may well be justified.
In October 2017, we had undercover eye tests at up to four branches of each optician across England and Wales. 13 out of 30 visits were rated as poor or very poor by our expert panel of optometrists, with lack of history-taking and inaccurate prescriptions letting some consultations down.
To get the best out of your eye test, use our guide to the eye tests you should expect, and tips on what to ask, below.
Is used to determine the strength of your glasses so your optometrist can see if your prescription has changed. You’ll be asked to hand your specs over and they will be placed on a machine – this often happens in the pre-testing before the appointment.
This test for glaucoma and can be easy to spot, as lots of optometrists use a method that blows puffs of air in your eye.
Look at your peripheral vision. This may be done with a technician before the appointment and involves you clicking a button as you see dots of light flash up in the edges of your vision.
Can be used to automatically estimate your prescription. You’ll be asked to look into a machine and most likely see a picture that will move in and out of focus.
Is the part where the optometrist will show you a series of lenses and ask you questions such as ‘clearer with or without’ or ‘sharper in 1 or 2’.
Is a microscope with a bright light used to look at the front and sometimes back of your eyes. You’ll place your chin in a chinrest and be asked to look straight ahead or at the optometrist’s ear.
Can be used to look at the inside of your eye, particularly the retina. Normally, the lights are turned down and the optometrist will come in close with a light and check your eyes in a variety of positions such as straight ahead, up, looking to the left and so on.
Is where a picture of the back of your eye is taken and stored, to create a record of your eye health, so that changes over time can be monitored. Your optometrist should show you the images later in your appointment – they are likely to look like orange/red circles with blood vessels running through. Some practices may also offer Optical Coherence Tomography ‘OCT’ 3D scanning of the eyes, though this usually costs extra.
Be proactive in describing any issue you're having to the optician. You'll be helping them to give you the best appointment:
Hover over the dots to decode your prescription.
Distance is the lens power prescribed to help you see distant objects clearly, this is based on your ability to read and eye chart with various lenses.
‘Sph’ (Sphere) A plus (+) sign means that your eye is long-sighted. A minus (-) that your eye is short-sighted. The number (for example +2.5) is the correction prescribed. The higher the number, the stronger the prescription lenses required.
‘Cyl’ (Cylinder) describes astigmatism (visual distortion caused by the shape of the eye) found. It tells you how far your eye is more rugby ball shaped than spherical. It can be written as either a plus or minus number.
‘Axis’ is a number between 0 and 180 which describes the angle in degrees of any rugby ball effect. This dictates how your lenses will be positioned.
Prism and Base is less common, but will show when you have a muscle imbalance in the eyes that prevent them from working together well. Prism lenses help correct this and prevent double vision.
OD & OS OD is the abbreviation for oculus dexter, the Latin term for right eye. OS means oculus sinister or left eye. If you see OU, it means oculus uterque or each eye, so the same measurement applies to both of your eyes.
Add is the 'reading addition' number which indicates the amount of additional correction needed when focusing at a close distance.
Small amounts of variation in prescriptions from different opticians are perfectly normal (even the same optician testing you on a different occasion) due to the subjective answers you give. However, this variation should not normally be greater than the equivalent of two steps in the power of the lens (0.50 dioptres).
Large variations may occur as a result of diabetes, and this would need further investigation.
A home (domiciliary) sight test can be carried out free in your own home by an experienced optician.
You can have this service if you qualify for a free NHS sight test but can't get to a high street optician store because of a mental or physical disability or mobility problems.
This includes having new glasses fitted and provided, as well as eye testing.
This can be arranged through your local NHS (GP) or NHS Direct if you live in England or Wales and NHS Helpline in Scotland.
It can be a really important way of helping someone housebound to stay living well at home, preventing accidents such as trips and falls due to poor eyesight.