Back to questions

What does it mean if my child tells me he has double vision?

When a child reports a change in his vision, it is important to understand where it comes from. Eye examinations may be necessary in order to institute appropriate treatment.

Pierre-François Kaeser, a university lecturer and clinical researcher, director of the paediatric strabology and ophthalmology unit, explains what to do if your child complains of double vision.

Understanding the visual disorders that cause double vision

If someone complains of seeing double, it can mean two things: 

  • That the two axes of the eyes are no longer parallel and no longer look at the same thing. 
  • That there may be a problem with the transparent media in one eye. The light is then displaced, and this is what causes double vision.

It is essential to know what eyesight disorder your child has so that you can offer appropriate treatment. To do this, you can start by performing a simple eye test at home. 

Testing your child’s vision

The difference between the two pathologies is quite easy to detect: just hide one eye. 

If double vision disappears when you hide one eye or the other, it means that it is linked to the fact that the two eyes are no longer parallel. 

If double vision persists when you hide one eye or the other, it means that it is linked to a refraction problem. E.g. within one eye. 

Other pathologies involved in double vision

Among the problems that can cause double vision symptoms, we may mention in particular: 

  • Cornea: astigmatism, dry eye, scar in the cornea 
  • Crystalline: cataract 
  • Eye muscle: due to a strabismus or a thyroid problem
  • Nerve: due to diabetes, multiple sclerosis
  • Brain: tumour, stroke

What are the consequences of a visual anomaly in which the eyes are not parallel?

A child may have visual axes that are not parallel from very early in life, sometimes from birth. This pathology is called diplopia. It can be monocular or binocular, with or without strabismus.

The brain does not appreciate this double vision and will remove the deviated image. The child may not fully develop his vision and suffer from amblyopia.

What is a refraction problem?

A refraction problem occurs when light that enters the eye does not focus properly on the retina due to an irregularity in the shape of the eye or its optical components. Refraction is the process by which light is bent (or refracted) as it passes through the different structures of the eye to eventually converge on the retina, where images are formed and sent to the brain.

This may cause blurred or distorted vision. Children with this type of vision problem need corrective lenses. 

Common refraction problems include myopia (clear near vision, blurred far vision), hyperopia (clear far vision, blurred near vision) and astigmatism (blurred vision at all distances).

Should I take my child to an eye specialist if he tells me he has double vision?

It is important to take your child’s symptoms seriously. If he says he is seeing double, it means that it is something new, that his vision has changed, probably due to the position of his eyes. It should not be swept aside. 

You should see an ophthalmologist immediately to determine the cause of this change in eye position. The ophthalmologist can then carry out an eye examination and institute appropriate treatment.

Find out more about children’s eye disorders

Now you know the two reasons why your child may be seeing double. Does your child have other symptoms? Perhaps he has blurred vision or suffers from headaches? Check out our page on visual symptoms in children to find out more.
Our ophthalmology specialists also explain what to do in case of dry eyeconjunctivitisnystagmus or congenital glaucoma.