Diseases and Conditions › Pediatric Ophthalmology › Refractive Errors

Refractive Errors

Jayesh N Doctor

Ophthalmic Surgeon, Doctor Eye Institute, Mumbai, India
First Created: 01/04/2001 Last Updated: 08/01/2015

Patient Education

Normal vision means the child is able to appreciate an object at a certain distance in its different proportions and colors.

When the baby is born, the two eyes don't move together and there is an absence of fixation to the light.

Around three months of age, the baby starts fixating the eyes on the light and around six to eight months of age both the eyes start moving together. Eyes start following the light source in different directions. When the eyes don't move together it will look as if the baby has developed a squint.

Initially, at an earlier age, the eyes are usually Hypermetropic (far-sighted) which gradually over a period of time changes into normal eyes. At times, the eyeball may enlarge more and the child may develop myopia (near-sightedness).

Normal eye

Here, the parallel rays of light are focused on the retina and the child is able to see clearly which is many times described as 6/6 or 20/20 vision. In other words, also described as emmetropia.

Hypermetropia

In this condition, the eyeball is shorter in length and the parallel rays of light are focused behind the retina leading to clear vision for the distant object but has to strain for near. When the strain is more a child may develop a convergent squint. This may occasionally lead to Amblyopia (lazy eye). Many a time convergent squint may be corrected by giving plus number spectacles (glasses) to the child.

Myopia

this condition due to elongated eyeball size the parallel rays of light are focused in front of the retina leading to the blurred vision for distant objects. Children may face symptoms like glare and photophobia and may develop a divergent squint. Giving a minus a number of glasses can treat myopia.

Astigmatism

In this condition, the curvature of the front surface of the eye known as the cornea is different in different meridians (axes). There may be a higher power in one meridian compared to the other. Due to this unevenness of the cornea, the rays of light are focused unevenly on the retina, resulting in a distorted image formation. For example, A circular image appears oval. The child may try to see objects by tilting the head, squinting the eyes, or by blinking excessively.

Nystagmus

Here, there is an involuntary oscillation of both the eyes associated with a refractive error. It is generally associated with albinism (absence of pigment melanin). The patient may face photophobia (intolerance to light) which can be treated by prescribing tinted glasses correcting the refractive error also.