USEFUL DISEASE A disease in it is never useful since it is a deviation from normality. Sometimes, rarely, a pathology produces a positive result, such as old-age hyperopia in short-sighted people, where the focal point occurs before the back wall of the eyeball. As hyperopia is when the focal point falls further back there is a moment in life where both aberrations are compensated and the patient can stop wearing lenses. But it's kind of unusual. 2 . It appears to be confused usefully with benign, which is a non-carcinogenic disease
