If nothing is embedded in the eye:

Rinse with saline solution. Flushing dust, grit and debris from an injured eye can provide immediate pain relief. But use only sterile saline that has been properly stored.

Apply a cold pack. Place a bag of ice, a commercial ice pack or even a bag of frozen peas directly over the closed eyelids. This will usually reduce swelling and make the horse more comfortable, particularly if the problem is conjunctivitisa swelling of the membranes around the globeor blunt trauma like a person’s “black eye,” which affects only the skin around the eye.