[Surface changes in glass eye prostheses]

The exposed surface of new glass eye protheses becomes rough and is destroyed in use. The changes in the exposed surfaces have been demonstrated by scanning electron microscopy and with thin sections under optical microscopes. The alteration process depends on the length of time the artificial eye is worn. The main cause is chemical attack of the glass surface in the tear fluid, which is usually slightly alkaline. Chronic conjunctival inflammation, appearing after a long period of wearing the same artificial eye, may be caused by mechanical irritation from the surface roughness.