A person with a short-sighted eye of more than 8 dioptres is more likely to suffer certain eye diseases like glaucoma and cataracts and, especially, pathologies related to the retina. An eye with a high degree of short-sightedness is longer than normal and its walls, including the retina, are very thin and thus they are more fragile and vulnerable. For this reason, thin areas in the peripheral retina which may be susceptible to retinal tearing and detachment are frequently established.
Likewise, the presence of degenerative lesions in the central retina (areas of choroidal atrophy and pigmented epithelial of the retina), neovessel growth in the macula, retina layer splitting (retinoschisis) and a macular hole are frequent in myopia magna. The symptoms that warrant an immediate visit to the ophthalmologist are the sudden appearance of photopsia and/or myodesopsia (flashes of light and "floaters"), seeing a dark stain in the centre or around the edge that increases and does not disappear and distortion of images. Early treatment usually improves the prognosis of these cases significantly.