Eye Specialist
Brussels, Belgium

Frequent eye diseases

Left, original picture with Niagara Falls in background. Right, picture seen by an hyperopic patient.

Vision of an hyperopic patient

Definition of hyperopia

Hyperopia is a refraction anomaly causing images to focus behind the retina.

This anomaly can be caused by a small eye and/or a lower convergence of most refractive elements of the eye, specially the cornea and lens.

An hyperopic patient has usually a good far vision. Indeed, the eye is able to accommodate all or part of the faulty convergence moving the image on the retina.

Usually, this ability of convergence is used to focus images in near vision. This ability of accommodation decreases progressively with age and causes presbyopia in emmetropic patients at the age of about 45 year-old.

The hyperopic patient can then have some difficulties in near vision because he uses some of his accommodation to compensate his hyperopia.

If the subject is young and hyperopia not too important, he will be able to compensate by accommadation at all time. Vision is always clear.

If the subject is older, he will start to have difficulties first in near vision as it requires the most important accommodation effort. Age increasing and accommodation ability decreasing, far vision will also be blurry as he will not be able to compensate anymore.

Because subject accommodates all the time, he will eventually complain of headaches and blurry vision moreoften at the end of the day.

Therefore, with age going on, vision will be clear at near and far distance, then will decrease first at near distance then at far distance.

Correction of hyperopia

To correct hyperopia, one needs to converge image rays to focus on retina. One can use a convergent glass or lens, therefore the value of the correction will be positive (+).

One can also correct hyperopia surgically by modifying most refractive elements of the eye i.e. cornea, the eye lens or by adding a convergent lens inside the eye.

Some points about hyperopia

Accommodation is normally used in near vision. Hyperopic patient accommodates to compensate and can develop a convergent strabism. Indeed when the eye goes in near vision and accommodate, it also converges i.e. moves toward the nose. Accommodation will simultaneously stimulaite eye convergence and give the impression that the hyperopic patient "squints toward his nose".

This can be the case in young children because the eye is smaller. This accommodative convergent strabism can be corrected by glasses or lenses to prevent bad visual maturation and defective 3D vision. When growing up, the eye can reach a normal size and the child becomes emmetropic.