Children and their eyes

Dr Ramesh Murthy, MD FRCS MNAMS
Consultant Pediatric Ophthalmology, Squint, Oculoplasty, Ocular Oncology, Neuroophthalmology
AXIS EYE FOUNDATION, Punjagutta, Hyderabad
04066363100, 9248063100


The prevalence of blindness among children varies between 0.2 /1000 to 1.5/1000 with a global estimate of 0.7/1000. This means that there are about 1.4 million blind children worldwide. It has been said that a child goes blind every minute. Children who are blind have to live a life of emotional, social and economic difficulties which affect the child, family and society.

However it is worthwhile to note that nearly 50% of the 1.4 million children blind worldwide are needlessly blind. Most of the causes of blindness are preventable. Refractive errors are easy to treat with simple prescription of glasses. Vision needs to be checked for all children by the age of 3 years by a qualified health care professional as the child will never express that it cannot see well. Other important causes of preventable blindness include “amblyopia” or lazy eye, squint and childhood cataract.

When there is a difference in refractive error between 2 eyes or the eyes have squint or the visual axis is blocked by a cataract or any white opacity, the eye does not see and the brain recognises the image from the better eye and ignores the image from the poorly-seeing eye. The weaker eye is called the laze eye. In the early stages this may be reversible, however as the child grows older this becomes more and more difficult to reverse. Early detection is essential. It is important to recognise this condition as this is very common and affects approximately 3 of every 100 children. Vision screening is essential to diagnose this condition as the eyes will appear normal. With prompt treatment a reversal is possible though in many cases beyond the age of 6 years the condition may not be completely curable. The reason is the vision pathways develop faster in childhood and their development is complete by about 8 -10 years of age. Simple home exercises like patching the good eye are prescribed or sometimes only eyedrops are administered. It is important that the child is under the regular care of an eye specialist to monitor the vision in the eyes. Parents and guardians have a vital role to play in the treatment of this condition. The treatment may be needed for a few months till the vision is completely improved and needs patience and perseverance. Recent research has shown that amblyopia or lazy eye can be cured even when the child is older.

Squint is a misalignment of the eyes so that both the eyes do not focus on the same point of interest. This deviation results from the failure of the eye muscles to work together. When a child is born the eyes may not be able to focus on objects. But by the age of 3 months, an infant’s eyes should have the ability to focus on small objects and the eyes should be straight. A six month old infant should be able to focus on both distant and near objects. It is important to detect and correct squint early as an uncorrected squint may lead to a lazy eye. A person with squint can use only one eye at a time whereas a person with properly aligned eyes will be able to use both eyes to judge distance and depth more accurately. Certain careers need good binocular vision. Squint can also affect the appearance and self confidence of a child. A squint is easy to spot. One eye maybe turned towards or away from the nose. But small squints may not be seen easily and may need an eye specialist to pick up these squints.

While in most cases the cause of squint is not obvious, various conditions like refractive errors, focussing problems, nerve injuries and poor sight due to a cataract can lead to squint. Sometimes squints run in families. A child with squint needs a full eye check up. Young children are uncooperative and sometimes this may mean need for examination under sedation. Treatment often involves spectacles to correct the refractive error and the glasses need to be worn most of the day. Lazy eye if present may need treatment as well with patching. Surgery to straighten the eyes may be needed not only to improve the appearance but also to ensure the child uses both eyes together. Surgery is straightforward and involves tightening or loosening the muscles. Surgery is very safe. Modern techniques ensure recovery in a day and resumption of activities the next day. The success of squint surgery is very high and frequent follow up is not required.

Childhood cataract comprises about 14% of preventable childhood blindness. Cataract refers to cloudiness of the normally clear lens. Contrary to popular belief, cataracts can occur in children. Cataracts can cause decreased vision by preventing the light rays from reaching the eye and can lead to a lazy eye or amblyopia which can be irreversible. While in most cases the cause of the cataract is unknown, some cases can occur in conjunction with a genetic or metabolic abnormality. Amongst the preventable causes of cataract, rubella induced cataract can be easily prevented with appropriate vaccination. An estimated 2,38,000 children are born with congenital rubella syndrome every year. In south India, about 25 % congenital cataracts are known to be associated with rubella. Rubella immunization of women of the child bearing age can prevent congenital rubella syndrome. Some forms of cataract are genetic and occur following marriages within families. Early identification is essential. Recognition of the cataract is usually by a family member or teacher as the child is not going to express that he or she has cataract. A whitish opacity may be apparent in the child’s eye. The child’s eye learns to see only when clear images get focussed in the eye. If this does not happen the child’s vision will not develop normally.

Urgent surgery is usually required followed by the use of glasses or contact lens. Surgery is not as straightforward as in adults and the child’s eye behaves differently from adults’ eyes. Recent advances in surgical techniques and lenses which can be implanted in the eye, have made the surgery quite safe and successful. The parents are as involved as the eye health professionals in the rehabilitation of the child. With specialised services and modern technology, the outcome of surgery has improved. Early recognition, early intervention and early rehabilitation will increase the probability of good visual results.

A child may appear normal and yet have a visual problem. In most cases the child is unable to convey the problem and hence the eye diseases can go undetected. Hence it is our duty to ensure that all children are examined at least once by a qualified eye health professional, before the third birthday.