Are my child’s eyes like my mother’s?

In my clinic, one of the most common questions I am asked when I diagnose the presence of a refractive error and start discussing spectacle wear is if this is hereditary.

‘Yes, it is possible’ is a simple, straightforward answer. However, parents of those who wear spectacles, especially those of high ‘numbers’, sometimes bring their child who has no complaints right now but wish to know what are the chances the child will end up needing to wear spectacles and how to avoid or postpone what seems inevitable. So, do genetics play a role in the development of refractive error or ‘power or number’ in local parlance?

Findings from studies vary widely. Here are some statistics. These vary according to the type of refractive error. The myopia prevalence in a child is 15% if one parent has myopia. This figure increases drastically to 44% if both parents have myopia.

The prevalence is different for hypermetropia (hyperopia) or ‘plus’ power. Infact, there is no clear consensus in literature about how often children of parents who have hyperopia may develop the same condition. Children with hyperopia may have less complaints and hence remain undetected.

The other condition, astigmatism, too, is not often detected in parents if it is of a lower degree as the symptoms may be vague or subtle and be attributed to headaches or eye strain. However, astigmatism is described in studies as having a significant genetic component. One study found that an older paternal age at birth increases the chance that a child may have astigmatism.

I think we can safely conclude that if a child’s parents, uncles, aunts, or grandparents started spectacle wear at a young age, then the child needs a complete eye exam, including dilation and testing for the presence of refractive error.