Photophobia

PHOTOphobia (photophobia) (from Greek -photos- light and phobeo- I fear), increased sensitivity of the eye to daylight or artificial light. A distinction is made between photophobia of superficial and deep origin. Photophobia of superficial origin is accompanied by painful sensations in the eye under the influence of irritation of the trigeminal nerve endings located in the anterior part of the eye. Photophobia is particularly sharply manifested in various processes of a superficial nature on the cornea (foreign bodies, erosions, superficial inflammations, etc.), which are characterized by the greatest painfulness. In addition to photophobia, such processes are usually accompanied by a sharp spasm of the eyelids and lacrimation. Photophobia of deep origin is rarely so strongly expressed and is accompanied by severe phenomena of blepharospasm and lacrimation. It is based on the direct irritation of the visual nerve elements of the retina by light. Retinal photophobia very often develops on completely healthy eyes, mainly in cases when an excessive amount of light rays enters the eye, as for example with too bright artificial lighting, when looking at the sun; photophobia especially easily arises with dilation of the pupils of one origin or another, as well as with albinism. Sometimes retinal photophobia is also observed in inflammatory diseases of the visual nerve apparatus (see Retinitis). Finally, photophobia can also be of central origin, as for example in neurasthenics and hysterics with increased sensitivity of the retina, and in the latter it is sometimes accompanied by clonic convulsions of the orbicular muscle of the orbit (tic convulsii). As a manifestation of organic suffering of the central nervous system, photophobia with a sensation of severe blinding is considered one of the signs of brain abscesses in the frontal lobe.-Treatment of photophobia comes down to treatment of the underlying disease. As a palliative for corneal photophobia, a 1-2% solution of cocaine is used in drops; for retinal photophobia-protective glasses with smoked, yellow and green tinted glass.