It’s important to remember that your child doesn’t have to be able to read or even talk in order to have an eye test. Children rarely complain about their sight which makes regular checks even more important, especially for determining conditions such as Astigmatism, where it’s hard to notice the symptoms.
What is astigmatism?
Astigmatism is a common condition where the cornea or lens of the eye isn’t a perfect curve, causing blurred or distorted vision. Like nearsightedness and farsightedness, astigmatism is a refractive error, meaning it’s not an eye disease or eye health problem - it’s simply a problem with how the eye focuses on light.
Eyes are naturally spherical in shape, but the eye of someone who has this condition is shaped more like a rugby ball. This means that when light enters the eye it’s refracted more in one direction than the other, allowing only part of the object to be in focus - resulting in blurred vision. In most cases with children, astigmatism is inherited and is often present at birth. However if left undiagnosed, it can lead to a lazy eye.
Whilst this condition is often present from birth, the NHS have listed other potential causes
- Injuries to the cornea, for example from an infection that scars the cornea
- Eye conditions that affect the eyelid and distort the cornea as a result
- Changes to the cornea as a result of eye surgery
- keratoconus and keratoglobus – eye conditions that cause the cornea to bulge, get thinner and change shape
What are the warning signs?
You will probably not notice anything wrong with your child’s vision if they have astigmatism. That’s not unusual as children will often accept poor vision without saying anything. After all, they may never have seen the world in focus so won’t know any different. However children with this condition may experience symptoms including:
- Difficulty focusing on printed words
- Tired eyes
- Sensitivity to light
Testing for astigmatism in children
A number of tests can be used if astigmatism is suspected. Below is an overview of the two most common tests for children:
- Visual acuity test. This test assess your child’s ability to focus on objects at different distances. It usually involves reading letters on a board, with the letters becoming progressively smaller on each line of the chart
- Keratometer test. A device called a keratometer can measure the degree of corneal astigmatism. It measures how light is being focused by the cornea and can detect irregularities in the curve of the cornea, by determining the steepest and flattest curves
How is astigmatism treated?
Almost all types of the condition can be corrected with properly prescribed glasses or special corrective lenses called toric lenses are prescribed. These corrective lenses bend the incoming light rays in a way that compensates for the error caused by faulty refraction so that images are properly received onto the retina. After performing the tests mentioned above, your optician will determine the ideal toric lens prescription for your child’s astigmatism. Glasses that are prescribed for this condition have greater strength in one direction of the lens than in the opposite direction. A prescription for astigmatism will have several numbers and will look something like this: -2.00 +2.50 X 90
Astigmatism is very common, with research suggesting most of us are born with some degree of it. Reading and concentrating at school may be affected if a child goes undiagnosed. Therefore, regular eye tests are extremely important.
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