Thanks for writing in.
Chronic kidney disease
is often associated with a retinopathy
which can cause symptoms similar to the ones you are describing. I am not sure whether the child you are talking about actually has chronic kidney disease. Frequent changes in prescription glasses are common on 13 year olds. However, these symptoms are not suggestive of a refractive error
. I would suggest that you see an ophthalmologist who can completely examine the retina
and rule out any serious disorder.
Hope this helps