Short and long sight
Myopia in childhood
Short-sightedness can develop at any age and in children tends to get worse as they grow. The younger they are when they start becoming short-sighted, generally the faster their vision deteriorates and the more severe it is in adulthood.
There is no single treatment available that appears to stop this progression. However, research has shown that atropine eye drops can slow the progression of short-sightedness, but it can cause side effects at high strengths – such as difficulty reading and sensitivity to bright light – and low-strength drops aren’t commercially available in the UK.
Orthokeratology and bifocal contact lenses may also slow down short-sight progression in children, but possibly not as much as the eye drops.
Long-sightedness is a confusing term since long-sightedness can affect people very differently at depending on the degree of long-sightedness and the age of the patient.
Clinically long-sightedness is known as Hyperopia; it is when the cornea is too flat, or the eye is too short, so light focuses, ‘behind’ the retina.
With a smaller degree of hyperopia, we may be able to overcome this defocus with help from the ciliary body which changes the shape of the lens and pulls the focussed light onto the retina. This can create clear vision in the distance.
The older patient or a patient with a higher degree of hyperopia, will not be able to overcome this defocus. Long-sightedness is very different to ‘presbyopia’ where we lose the ability to see near objects, when our eyes are fully corrected for distance.
Hyperopia in Childhood
Astigmatism occurs when the eye is a less rounded shape than usual. Often referred to as being shaped more like a rugby ball (toroidal) rather than a football (Spherical). Astigmatism is created when the cornea of the eye has two different degrees of curvature, one steeper and one flatter which makes it impossible for the eye to focus light perfectly onto the retina.
People with astigmatism will often be able to see vertical objects clearly but horizontal ones may be blurred, or vice versa. Astigmatism is a common disorder, which often co-exists with short or long-sightedness.