The person with one of the chronic glaucomas frequently is unaware that the damage is present in the eye. Like the hands of a clock, it moves so slowly that its progress is not noticed. On the other hand, acute glaucoma, in which the intraocular pressure rises rapidly, often causes symptoms, which may be severe.

Symptoms that suggest the presence of chronic or acute glaucoma include:

• blurred or indistinct vision
• poor vision under low light conditions
• sensation of a blind area
• eye or headaches associated with exercise
• aching pain in the eye associated with a red eye
• misty vision and colored halos around lights

When symptoms of glaucoma occur acutely (that is, suddenly) and severely, it can be very painful and/or eyesight can worsen. If this happens, treatment needs to be started within hours. Early diagnosis is the key to corrective action.