Primary Open Angle Glaucoma is an inherited condition of the eye affecting dogs. Affected dogs typically develop increased eye pressure in both eyes between 8 to 16 months of age. As the pressure in the eye increases, the eyeball increases in size and is painful. Signs of pain in the eye include excessive blinking, tearing and redness. If left untreated, the increased pressure in the eye leads to optic nerve damage and the gradual loss of vision. Most dogs exhibit luxation of the lens of the eye by 2.5 years of age. Symptoms of lens luxation include excessive blinking, squinting and tearing of the eye. Dislocation of the lens can occur in both the forward and backward position within the eye, but dislocation in the forward position is more common and serious. If not treated immediately, lens dislocation will exasperate the glaucoma and vision loss. Other symptoms may include bulging eyes and cataracts.