Photopsia

Photopsia (photo-light and opsis-I see), scintillatio, abnormal light sensations in the eyes in the form of sparks, flashes, lightning, fiery surfaces, glowing rings, lines, etc., of a purely subjective nature. Photopsias belong to the so-called entoptic phenomena, as they are caused by factors inherent in the eyes themselves, rather than by ordinary light stimuli coming from outside, and therefore as a product of purely local excitation, they can occur in one eye, in complete darkness, and even in blind, completely atrophied eyes. The main causes of photopsias are various pathological processes of the vascular membrane and the visual-nerve apparatus, both inflammatory and non-inflammatory in nature—such as tumors, detachment of the retina, etc., which cause focal irritation of the terminal nerve elements; further, photopsias can also be of central origin, as they are often complained of by patients suffering from functional disorders of the nervous system; this must also include photopsias as one of the symptoms of so-called ocular migraine, or 'scintillating scotoma,' developing on the basis of circulatory disorders of the cerebral cortex. Finally, they can be caused by so-called inadequate stimuli in the form of pressure on the eye, blows, electric current, etc.—Photopsias, even of relatively innocent origin, but more or less systematic and persistent in nature, constitute a rather distressing phenomenon for patients, as they usually affect them in a very depressing manner, especially in impressionable individuals; moreover, if the source of photopsias is a blind eye, they can significantly disrupt the normal function of the healthy eye and serve as an indication for complete removal of the diseased eye. In other cases, their therapy is reduced to eliminating the underlying disease.