Initially, there may be a slight decrease in vision, the appearance of coloured halos around bright objects and pain in the eye and head. After a few hours the symptoms become much more severe with rapid loss of vision and sudden, severe throbbing pain in the eye. The eyelid swells and the eye becomes red and watery, with a dilated pupil that doesn t respond to light by closing, as it should. There may be nausea and vomiting. Although most symptoms disappear after treatment with medication, there may be some remaining loss of peripheral vision.
Attacks can re-occur.
If they do so, then each one tends to further reduce the field of vision. This is usually done with a tonometer , of which there are two basic types. The simplest uses a puff of air blown against the surface of the eye. More commonly, a Goldman tonometer is used, as this gives more accurate measurements. Using a microscope, the tonometer is then brought in close so that it lightly touches the surface of the eye.