Astigmatism

Astigmatism is not ‘a stigma’, it is just the name for the third most common type of refractive error. Hyperopia and myopia are the commonest and are corrected with spherical (sph) lenses whereas astigmatism is a bit special as it needs a different type of correcting lens a  cylindrical shaped lens (cyl). An eye with uncorrected astigmatism sees shapes stretched out of shape, and fuzzy in one direction. The brain’s visual centres hate fuzzy vision so they send messages to the eye to compensate which only creates more complications.

If both eyes have a similar but small astigmatic prescription then spectacles may not need to be worn all the time, but if they are never worn then vision never improves. And if left uncorrected then the visual acuity (best achievable vision) may only be correctable to the minimum level required for driving (i.e. 2 or 3 lines worse than the best vision that a healthy eyes should be able to achieve).  In fact the brain finds it increasingly difficult to accept good vision with the result that a child or adult finds it difficult to ‘get on with their glasses’, even though their poor vision maybe causing headaches and eyestrain,

If one eye has a high level of astigmatism then that eye may (and if left uncorrected usually does) become lazy. Even though one eye may have good vision spectacles need to be worn constantly to equalise the acuities.

Contact lenses for correcting astigmatism are termed toric lenses. Contact lens wear did not used to be an easy option for people with high levels of astigmatism. However modern materials and digital lens designs mean that most prescriptions can now be fitted. Some toric lenses are just as easy to fit as normal spherical lenses although they are a bit more expensive. High levels of astigmatism require more complex fitting and the lenses are more expensive so lens wear so a more expensive option but may give more comfortable vision than spectacles.

Children can be fitted with contact lenses as soon as they can understand the importance of hand hygiene and are able to insert and remove lenses themselves. If a child finds distance vision blurry and feels uncomfortable without their glasses this can stop them taking part in sport. Skills learnt from participating in sport play an important role in a child’s all round development (mental, physical and character building) so they should be encouraged to participate in something they enjoy. For some children this may mean them wearing contact lenses at a younger age than might otherwise be thought appropriate. The age at which a child commences contact lens wear is something that needs to be discussed by the child, the parent and an eye care specialist.

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