Eye tests play a huge part in making sure your eyes stay healthy. Not only are they important for indicating whether you need to start wearing glasses or need to change your prescription, but also for detecting some common eye conditions.
How often should you have an eye test?
We recommend that you have an eye test at least every two years. If your optometrist doesn’t have any concerns about your vision or eye health, adults should have one every two years, and children should visit every year. But if you are ever concerned about your vision, at any point, then just book an appointment and we can take a look.
Some people may be at a higher risk of developing problems with their sight, including:
Those with a family history of glaucoma
Those aged 40 or over
Those aged 60 or over
If you fall into these categories, it’s worth speaking to your optician to find out how often you should have your eyes tested.
What happens at an eye test?
An eye test involves a series of checks to assess your vision and check the overall health of your eyes. More than checking your vision, it’s an overall eye health check, inside and out. Eyes can be affected by several conditions which may be picked up early through an eye test, giving it less chance of affecting your vision. Your eyes can even indicate signs of general health problems like hypertension and diabetes.
Diseases found by an eye test can, very rarely, be life-threatening, so eye examinations are an important part of your regular health checks. There are four main parts involved in a typical eye test:
History and symptoms
This gives you the opportunity to discuss any concerns you have about your eyes, vision or current glasses, and any symptoms you’re experiencing which might need further investigation. The optometrist will ask about your general health, medications, any past treatment on your eyes, or any family members with existing eye conditions. This information helps us to tailor the vision test to best suit your needs.
Before your full eye exam, you will have a pre-test with one of our optical assistants. Depending on your individual needs, a variety of different pieces of diagnostic equipment can be used in the pre-test, including:
Eye pressure test (tonometer):
A tonometer will blow a gentle puff of air onto the surface of each eye to measure the internal pressure, which can help assess your risk of developing glaucoma.
Digital retinal photography (DRP):
The optical assistant may take a photograph of the back of your eyes using a fundus camera. This image will be saved to monitor any changes in eye health on future visits.
This machine measures the ability of your eyes to focus, helping to assess how long- or short-sighted you are. You will stare into the machine through two lenses and focus on a picture appearing closer and then further away, which helps to calculate an estimation of your prescription. Learn more about autorefractor tests here.
The main eye tests
The optometrist will then check the health of your eyes and look for signs of other medical conditions. They will ask you if you are experiencing any eye problems and about your general eye health and lifestyle. It is important to have a clear understanding of your needs so that we can select the best management plan and/or corrective lenses for you.
This vision test is used to assess how well your eyes can focus, helping to determine how long- or short-sighted you are. While focusing on something in the distance, your optometrist will shine a light in each eye, placing different lenses in front of them to help calculate your prescription.
The optometrist will ask you to read from a Snellen chart (also known as the letter chart test). This measures your visual acuity (i.e. how well you can see with and without lenses in front of your eyes) to determine whether you have 20/20 vision or whether a prescription is needed to give you the best vision possible.
This specialist torch is used to examine the retina at the back of the eye, your optic nerve and its blood vessels to make sure they are healthy.
Slit lamp test:
A slit lamp (also known as a Volk lens) is a powerful microscope used to examine the front surface of the eyes (cornea, iris and lens) for abnormalities or scratches, which is particularly important for contact lens wearers.
Visual field check:
This test will assess your ability to detect flashes of light in your peripheral (outer) vision. Visual field tests are often used to detect early stages of glaucoma or any conditions that could be associated with headaches and other health issues.
OCT (Optical Coherence Tomography) is a hospital-grade eye scan that helps to view the structures of your eye in greater detail, helping spot signs of eye conditions like glaucoma and diabetic retinopathy up to four years earlier than traditional methods. They only take a few seconds to complete — just ask your local store if they offer OCT scanning so you can add it to your normal eye test.
Summary and advice
Once all the relevant tests have been carried out, your optometrist will be able to discuss the results and offer any advice. This could be a simple ‘all clear’ on the eye health front, or they might talk you through particular lens options to match your prescription and lifestyle. Treatments for any eye conditions are also discussed at this point, as well as possible referral to a specialist.
Understanding your eye test results
At the end of your eye test, the optometrist will give you a copy of the prescription and can answer any further questions you may have. They can also help you understand and read your prescription, if you need one, and will then recommend the best options for you.
Do I need an eye test?
It’s recommended that you have an eye exam at least every two years, however if you’ve noticed a change in your vision, it’s best to get your vision tested.
Check out our resources below to help you get started: