Your pet does not read (other than your lips for w-a-l-k) and he relies more on senses such as smell and sound than vision for navigation. Therefore, in veterinary medicine we do not usually deal with problems concerning the power of vision.
However, diseases of the eye are perhaps more common among animals than in human medicine. Most commonly, pets with allergies suffer from eye symptoms; certain breeds with prominent eyes are prone to suffer eye traumas, corneal ulcers, and dry eyes; and cats suffer infectious diseases that affect the eyes (e.g. calicivirus, rhinotracheitis). Some breeds are predisposed to suffer autoimmune diseases of the eye (pannus); glaucoma affects both cats and dogs.
If your pet has trouble with his eyes, we have specialized testing and equipment available for tear production, intraocular pressure (inside the eye), staining of cornea to detect ulcers, and evaluation of the retina. Complex cases are referred to the Atlantic Veterinary College.
Most diseases of the eyes can be treated with medication. Some require surgery, particularly to stimulate the healing of corneal ulcers, resolve red eye, or to remove tumors from the eyelids.