Are online vision tests reliable?

With the help of digital technologies, it is now possible to easily perform online vision tests for free. They are often found on the websites of opticians. 

You will be offered the opportunity to screen for various eye diseases or vision disorders: myopia, astigmatism, and hyperopia, by evaluating distance or near vision. Or the perception of colours, the visual field, binocular vision and photosensitivity. 

But are these online tests really reliable? Pierre-François Kaeser, a university lecturer and clinical researcher, director of the paediatric strabology and ophthalmology unit, gives us his vision of the issue.

How is vision screening performed online?

Tests are usually done via a computer or smartphone application. Depending on the pathology sought, online eye examinations vary. For example, to assess the visual field, a simple pencil placed in front of the eyes will suffice.

If the child has a correction, he will have to wear his glasses. Generally, the online eye test takes only a few minutes. 

What are the limitations of these online vision tests?

Online vision tests are self-tests that require a certain amount of autonomy. A child will not be independent enough to carry them out alone.

It is also important to understand that there is no calibration on the various tests carried out on the Internet. This means that a visual disorder can go unnoticed. A virtual test will not quantify visual problems. 

Is it useful to give a child an online vision exam? 

On the Internet, it is very difficult to evaluate the coordination of the two eyes, the ability to see in three dimensions, or the motility of the eye. So there are many visual disorders that go completely unnoticed.

However, it can be useful to compare the vision between the two eyes. If you notice a difference, a check-up with an eye examination by an ophthalmologist is recommended. For example, it can define whether the child is myopic, hyperopic, or astigmatic. 

In conclusion, an online test can eventually lead to a consultation if in doubt. However, a test described as “normal” on the Internet cannot truly reassure. 

Going further in checking your children’s eyesight

Have you noticed that your child has a problem with colour vision, with near or far vision or that he complains of headaches or migraines, visual fatigue or blurred vision? 

It is then best to see your paediatrician or ophthalmologist to establish an accurate visual assessment and make a correction as soon as possible to ensure his visual health. As a reminder, any eye problem detected early will have a better chance of being corrected.