Why can children have “perfect eye sight” and still experience distortion?
An optometrist (previously known as an ophthalmic optician) will report “perfect eye sight” when someone can see a letter chart without needing refractive correction (glasses), and when there are no (orthoptic) problems of co-ordination between the eyes. The perceptual distortions may occur quite independently of any refractive error, although they are often, but not always, associated with a mild binocular vision difficulty (i.e. a difficulty in moving the eyes together, keeping the direction of gaze appropriately co-ordinated). In most cases the binocular difficulties do not appear to be the basis for the distortions.
