Do Online Eye Tests Really Work?

Online eye tests seem to be the next big thing in optometry. After reading this article you will know for whom they work and why they can not replace a real eye exam because of the limitations they come with.

Always when testing your visual acuity certain distances need to be set. This is true for the online eye test as well as the eye exam at your local optician or optometrist. This ensures your eye muscles are relaxed and this way the right prescription can be measured for the distance.

After this first setup process, the actual eye test for measuring your prescription consists of several steps in which you get asked if you can see certain objects and how you see them. The process is actually pretty straight forward and normal eye tests work in a similar fashion as online eye tests do.

When you see two objects blurred because of myopia they overlap a little. When you see them clear they will not overlap. Depending on how big the gap between the objects is you can still see, your needed prescription can be calculated. These calculations are based on averages and can vary from person to person.

Those things can be considered in a comprehensive test design like from your local optical shop. In an already very limited test setting in an online eye test you probably will not reach maximum visual comfort.

Online Eye Tests Work For:

  • mild myopia
  • mild astigmatism

With those eye conditions, you can see clearly in a certain distance. But with hyperopia, this test process falls short. Because with a little more muscle tension you can easily pass the online eye test with “a perfect score”. The problem is after hours passing throughout the day the added muscle tension can lead to headaches or blurry vision.

Especially with astigmatism, you can also have a component of hyperopia in your prescription where those online tests will fall short. I think those online tests are better than not testing at all but they can not do one thing better compared to a regular eye test of your visual acuity.

One thing that really stood out to me when I saw the setup process for an online eye test first was each eye gets tested on its own. And that is it. But this is just the first part of a normal eye test.

After checking each eye on its own your eye care specialist will go on and check how your eyes play together with sophisticated tests and performs the fine-tuning of your prescription.

This is missing with online eye tests. But on the other hand, the customer should know if he or she has myopia or astigmatism so the test can work. But this is a prerequisite of information a lot of people do not have.

When you seek the advice of a professional you usually do not know where the problem can be related to. But before entering the online eye test you should know into which category your prescription falls. Even though your prescription changes over time! This is the main reason why you should visit your eye care specialist.

I am an optician I am all about innovation when it makes something better. This is not the case with online eye tests. Depending on the the eye conditions you have 50% of them will be measured accurately.

As I stated before the myopic component and astigmatism can be measured pretty easily with an online eye test. But just for fun let us look at the cases the online eye test will detect pretty good and which ones where it will not work perfectly.

As you can see in the illustration above the light rays will fall differently in your eye and land on your retina depending on the lens power you need. In the picture are various cases that work and some that will not work accurately. Which one do you have in which eye? Do you know? Should you go on to make the online eye test or not?

This is exactly why I am critical of online eye tests. You as a customer just do not know a lot of things and you do not understand the limitations of the online eye test. With a comprehensive eye test, the eye care professional also takes a closer look at your eyes and can fairly easily see irregularities on your eyes or if you have problems with dry eyes.

Problems with dry eyes can heavily influence measured astigmatism within the eye test. An optician looking at your eyes before testing your prescription will immediately know what is going on with your eyes. Where is the check-up when it comes to the online eye test?

Of course, my opinion as a master optician with optical shops is biased but looking at the online eye tests it is less of innovation to me rather than the approach how cheap can the industry go and the wearer/user still have a certain acceptance of the prescription of the online eye test.

But when the ideal prescription is not prescribed the visual capabilities will be limited. This includes the perception of depth, walking stairs, driving the car, and learning. In an optical shop, an experienced optician/optometrist can tell by the reactions of a wearer of glasses what is going on with the new RX and can assist the person wearing it.

The lens power does not be very high to produce problems. But when it comes to studies online vision tests seem to work and seem to be a valid option to the traditional approach where the testing frame is used. Like in this study here.

Where Can I Get a Prescription Online?

You can get your prescription for glasses or contacts at those websites.

The Cost of Online Eye Tests

The cost varies form 19$ – 35$ depending on the provider.

The Reviews of Online Vision Tests

When I looked for reviews I could not find much on the web. That was a little odd. I thought a lot of people would be using this technology because it is available since 2017. My searches showed some recalls as you can see in the screenshots.

After I saw the search results on google I hopped to the visibly site to see if I missed something and they are out of business. But they are not. You can still do the online vision test.


Online vision tests are not a substitute for an eye exam. Despite the price and the convenience of doing them at home, they provide less accuracy, fewer control feedbacks, and the possibility of not detected eye conditions an eye care professional would see immediately.

I wish you a great day.

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