Common eye diseases in dogs:

1. Corneal ulcer: Corneal ulcer is usually caused by external injury or disease. Symptoms of dogs suffering from corneal ulcers include inability to open part of the eyes, repeated eye rubbing, and excessive tears.

2. Epiphora: If the dog's tear discharge is so large that it affects the color of the eye coat, it may be caused by epiphora.

3. Congenital eyelid and eyelash problems: The most common eyelid deformities are entropion and ectropion. The eyelids turn inward, causing eyelashes to pierce into the eyes.

4. Conjunctivitis: If there is redness and swelling inside the dog’s eyes, it may be conjunctivitis.

5. Trichiasis: Trichiasis is a condition that often occurs in dogs. There are many special breeds that are more likely to occur, such as Chow Chow.

6. Cherry eyes: If you find that your dog has cherry eyes, you should take your dog to the hospital immediately for third eyelid gland embedding surgery.