Refractive Errors in Children

Myopia (known as near-sightedness)

In a myopic eye, the eyeball is too long or the cornea is too curved. The light rays are brought to a focal point of the retina, resulting in a blurred image for far. Images for near remain clear.

Myopia Illustration

Spending too many hours playing games on hand-held electronic devices, watching TV and reading may contribute to the development of myopia. Always take an eye break after 30 to 40 minutes of near work activities or spending time on outdoor activities may reduce the risk of developing myopia.

Treatment

Children first undergo a full Ophthalmic examination which may include:

• Refraction(checking the degree of myopia in the ‘natural’ state)
• Cyclorefraction (testing of the degree of myopia using eye drops which relax the internal muscles of the eye)
• Assessment of eye movements
• Examination of the front and back segments of the eye
• Non-contact measurement of the length of the eyeball using a special laser called an optical biometer)

After taking a comprehensive history of the patient eye and general health, treatment may be recommended.

Atropine 0.01% has virtually no side effects and have been shown to reduce myopia progression by 40 to 60% in local studies.  Myovision and OK contact lenses work by making the image seen by the eye fall either in focus on the retina or within the eyeball.  It is thought that this reduces the tendency for the eye to grow longer which is what happens in myopia progression.

Hyperopia (known as far-sightedness)

In a hyperopic eye, the eyeball is too short or the cornea is too flat. The light rays are brought to a focal point behind the retina, resulting in blurred images for far and near.

As most children are farsighted, they may not experience symptoms of blurry vision as their eyes are able to bend the light rays to place them directly on the retina.

Hyperopia Illustration

Treatment

The mainstay correction of hyperopia is by means of spectacles. However, children with hyperopia should be screened for squints (misaligned eyes) and amblyopia (lazy eye) to ensure proper development of their vision.

Astigmatism

Astigmatism can occur with myopia and hyperopia. In an astigmatic eye, the cornea has an uneven curvature. The light rays do not converge to one focal point. They merge in a line in front or behind the retina resulting in a distorted view.

Children who have astigmatism symptoms such as blurry vision or distorted vision may not be aware of this condition and this would affect child’s performance in school.

Astigmatism Illustration

Treatment

The mainstay correction of astigmatism is by means of spectacles. However, children with hyperopia should be screened for corneal disease and amblyopia (lazy eye) to ensure proper development of their vision.

Symptoms of refractive errors

• Double vision
• Blurred vision
• Haziness
• Glare or halos around bright lights
• Squinting
• Headaches
• Eye strain