Small white dots on the edge of the black eye are mainly caused by the following conditions: 1. It is caused by vesicular conjunctivitis, which is also the most common condition and is related to autoimmune reaction as well as cross-immune reaction caused by streptococcal infection and tuberculosis infection. The conjunctival congestion usually occurs around the small white vesicles, and patients experience foreign body sensation, stinging, and itching in the eyes. 2. It is caused by marginal corneal ulcers, and autoimmune reactions and infectious factors are the causes. It usually appears in a circular pattern at the edge of the cornea, early as a single small white dot, gradually fusing throughout the entire corneal limbus. 3. It is the appearance of small white dots on the outer white of the corneal limbus, usually due to lid spots. They are usually harmless and do not cause abnormal sensations and do not require special treatment.