by Jamie Bartlett

What do they do in an eye test?


You'll already know this…

Your eye examination test is super important.

During your visit, the optometrist will asses your vision to determine whether or not you require glasses or contact lenses.

If you do need glasses, it can be a big change to daily life. But fear not. Besides letting you see better, wearing glasses is a good way to be more comfortable and can dramatically improve the most basic of visual tasks.

Additionally, your eye test is a crucial way to detect any conditions that would otherwise go unnoticed. Eye-related symptoms can be very discreet, giving you no indication that there is anything wrong. It's a pretty good reason to attend once every two years.

If you have never had your eyes tested, here's what you can expect to happen.



What can I expect at an eye exam?



Eye muscle test

What happens in eye test?

Holding a pen or small torch, your optometrist will ask you to visually-track the item as they slowly wave it from side to side and up and down.

As your doing this, as hypnotic as it may feel, your optometrist will watch how your eyes behave as they trace the moving object.

This test is designed to detect muscle weakness or if you have poor control in your eyes.

Easy right?



Visual acuity

Even if you've never had your eyes tested, you’ll have seen this famous eye test chart.

Looking at a Snellen chart or a logMAR chart, the optometrist will ask you to read varying sizes of letters through varying strengths of lenses. Your optometrist will run through a carousel of lenses for both of your eyes.

As you progress through the rows of letters, they become incrementally smaller, making them harder to see.

Verbally, you can describe which combination of lenses gives you the sharpest amount of focus.

This test is carried out on each eye separately to determine your visual acuity.



Refraction assessment

Next, your optometrist will assess your eye’s ability to refract light.

As light enters your cornea and crystalline lens, it should normally be ‘bent’ into focus. This can be assessed using a retinoscope where light is shone into your eye to determine if you have any refractive errors.

If your eye/s struggle to do this effectively, you’ll very likely need to wear prescriptive correction via glasses or contact lenses.

This part of your eye test helps to determine the best strength of prescription your eyes need to give you the sharpest correction of vision.




What happens in eye test?

You may difficulty with your field of vision.

This is how far you can see to each side, without moving your eyes. To test this, your optometrist can carry out three different types of test.

  • Automated Perimetry: Looking directly at a screen with lots of blinking lights, you will be asked to notify your optometrist when you seem them blink.
  • Tangent: Much like the previous test, the tangent method is carried out using a digital screen. Simulated objects or shapes will appear in the far corners of the screen and you will be asked if or when you see them.
  • Confrontation: Covering one of your eyes, your optometrist will sit right in front of you. They will hover their left or right hand in various parts of your visual periphery to test how far you can see in each direction whilst looking straight ahead.

From any or all of these tests, your field of vision can be accurately assessed by your optometrist. Blind spots can be detected in certain areas of your eye which can help diagnose certain eye conditions.




Colour vision

Approximately 8% of people are reported to be colour deficient.

Very few people are completely colour blind which can have an effect on your education and career choice.

The test for colour deficiency involves looking at different colours of dots in various patterns. Within the dots are coloured, random numbers which you should be able to detect.

It is quickly distinguishable if you have a colour vision deficiency if you struggle to see these.




A beam of light

Next, your optometrist will gently shine an intense beam of light into your eye.

It’s not as dazzling as you’d expect so don’t worry. Using what is called a slit lamp, your optometrist can examine various part of the front of your eye. This assessment primarily concerns your eyelashes, iris, lens and fluid chamber.

This part of your eye test can feel marginally intrusive or harsh but an experienced optometrist will do their best to make it as brief as possible.




Retinal examination

To examine the back of your eye, your optometrist will use what is called an ophthalmoscope.

This examination allows your optometrist to see your retina at a good level of detail.

This process is used to asses your optic disk and retina and may require the use of eye-drops. Whilst they are not always necessary, eye-drops can be used to make your pupils dilate to make it easier to asses the back of your eye.

If eye-drops are administered, it's best that you bring a chaperone to drive you home. Ask your optometrist in advance of your appointment if they will use eye-drops during your eye-test.





She wears spectacle model: D - BL


A puff of air.

Using a non-contact tonometer, the optometrist will puff a small amount of air into your eye.

Most, if not all types of eye tests will include this process for the detection of the eye condition called glaucoma.

This condition is preventable and avoids the build-up of pressure from liquid in the eye. If undetected, this pressure can eventually lead to damage of the optic nerve. Over time, glaucoma can lead to long-term damage and even the loss of vision.

For the sake of a puff of air, this part of your eye tests is a breeze.




Eyesight test results explained

Resulting from these tests, you’ll be informed if you happen to have any particular defects.

In the unlikely event of any notable conditions, these will be discussed between you and your optometrist about the necessary steps, precautions or medical intervention.

You can expect to hear about:

  • Your visual acuity and the potential requirement for a prescription.
  • Your peripheral vision.
  • Your ability to see colour properly.
  • Your overall internal and external eye/s condition.
  • Any underlying eye conditions such as glaucoma, cataract or any issues with your retinas.




Image of our optical stockist Eyeroom based in Leeds, UK.


There you have it, a basic run-through of what happens in eye test practices.

One every two years, this quick test can be the best thing you can do to prevent any underlying eye conditions. It could quite literally save your sight!

If you being to experience any noticeable changes in your vision, you should contact your local optometrist as soon as you can. Give yourself peace of mind by going at least every two years, especially if you're susceptible to conditions such as glaucoma, diabetes or cataracts. 

The onset of blurriness, flashes of light, double vision or poor night vision are definitely worth mentioning before and during your appointment.

So go ahead... set your phone reminder or book-in with your local optician.

You're all set.



Jamie Bartlett: co-founder  |  Depending on where you live and your personal circumstances, you may be eligible for a free eye test in the UK.

Find out about your eye test cost with our blog post: Are eye tests free?

Feel free to use the social icons below to share this article.



Jamie Bartlett
Jamie Bartlett

Co-founder of Banton Frameworks.

Also in Eye care

Are eye tests free?

by Lucy Ross

Depending on where you live and your personal circumstances, your test can be free of charge. Discover if your eligible...
Read More
The unseen test after your eye test.

by Jamie Bartlett

After your eye test, here's some pointers about what to expect and the things you should ask for.
Read More
Astigmatism: what is it?

by Jamie Bartlett

Read about the symptoms and causes of astigmatism and the ways of which it can be corrected.
Read More