Severe squinting with spasms of the muscles around the eye is a symptom of a painful eye. Any painful eye condition can cause squinting. The tightening of the muscles rolls the eyelids in against the eye. Once rolled in, the rough edges of the lids and the hairs rub against the eyeball, causing further pain and spasms.
Treatment: Anesthetic drops can be applied to the eyeball to relieve the pain and break the cycle. The relief is temporary, unless the irritating factor is identified and removed.