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Refractive errors

What are Refractive errors

Refractive errors are abnormalities in the optical system of the eye that prevent the formation of a sharp image at different distances. This is the most common and best known eye condition and includes several types:

Spherical aberrations

Spherical aberrations occur when the eye’s optical power is too high or too low to properly project light onto the retina, the light-sensitive ‘screen’ at the back of the eye. Examples of this are:


Myopia is better known as near sightedness. Near sightedness causes images that a person sees in the distance to be blurry, while images close to the eye are sharp.


Hyperopia is better known as farsightedness. Farsightedness ensures that images a person sees in the distance are sharp, while images close to the eye are blurred.

The realization that vision has been affected by a refractive error can be difficult to accept. Knowing that one is not alone may provide support. There are many people in the same situation, some who have just been diagnosed and some who have been living with a refractive error for years.

If one experiences visual impairment as a result of refractive errors, then there are devices available that help with the tasks one has difficulty with. These aids can provide support with tasks that require vision and can help you continue to lead a full and independent life.

Image view without and with refractive errors
Left: normal vision. Right: view with a refractive error

Cylindrical deviations

Cylindrical abnormalities occur when the optical power of the eye is too strong or too weak. Examples of this are:


Astigmatism is caused by an irregularly shaped cornea (the cornea is responsible for the projection of images onto the retina). In an eye with astigmatism, some parts of the image are projected behind (or in front of) the retina, while other parts of the image end up on the retina. The result is that the image is not completely sharp.


Presbyopia is also called age-related visual impairment. With age, the flexibility of the eye lens decreases, resulting in the eye being unable to focus properly on objects close to the eye.

Refractive errors affect a large part of society – many people are affected by this to a greater or lesser extent.

What are the symptoms of refractive errors?

The symptoms of refractive errors vary per individual:

What can one expect from refractive errors?

How refractive errors are treated depends on the amount and severity of the condition. Glasses and lenses are often used to correct the blurred images caused by a refractive error. In some cases, surgery can resolve the complaints. Discuss the options with the doctor or specialist.

More information about refractive errors

Extensive information is available about refractive errors. This information is intended to inform you about the most important aspects of this eye condition and is not intended to replace the information one receives from the doctor or eye specialist.

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