An eye examination can be performed easily and does not require any technical expertise. It will provide you with the type of information you need to determine if this is an emergency. When in doubt, consider any change in the eye to be an emergency.
The examination is best done in a dark room using a single light source, such as a flashlight. A magnifying glass will help you see fine details on the surface of the eye. Have an assistant restrain the dog, as described in Restraining for Examination and Treatment.
First compare one eye to the other. Are they the same size, shape, and color? Are the pupils equal in size? (Remember, if you shine a light directly into an eye, the pupil will shrink.) Is there a discharge, and if so, is it watery or mucoid? Is the dog squinting? Is the nictitating membrane visible? Does the cornea look smoky, hazy, or cloudy? Is it painful to the dog when you press gently on the eyeball through closed eyelids?
To examine the surface of the eyeball, place one thumb against the skin of the cheek below the eye and the other thumb against the ridge of bone above. Gently draw down with the lower thumb and apply counter traction with the other. Because of the mobility of the skin of the dog’s face, the lower eyelid will sag out and you can look in and see the conjunctival sac and most of the cornea behind it. Reverse the procedure to examine the eye behind the upper eyelid. Flash a light across the surface of the cornea to see if it is clear and transparent. Any dull or dished-out spot is an indication of corneal abrasion or ulcer.
Press gently on the surface of the eye through the closed eyelids to see if one eye feels harder or softer than the other. If the eye is tender, the dog will give evidence of pain.
To test the dog’s vision, cover one eye and make a movement as if you are about to touch the other eye with your finger. If the dog has vision in that eye, he will blink as he sees your finger approaching.
Do not neglect minor eye ailments. If there is any doubt about the diagnosis, and particularly if the eye has been treated at home but has not shown improvement in 24 hours, call your veterinarian. Eye problems can go from minor to serious in a very short time.