Hello and welcome to Just Answer. I am a licensed veterinarian and would be happy to answer your questions.
When did this happen?
Does it appear that the eyeball itself is swollen or the whole area around the eye?
Is the eyeball red or inflammed looking? Is he squinting? Are his pupils responding to light? Can he blink?
Thanks and I will respond when you reply.
It happened this morning & its slowly gotten worse over the day.
The eye does not look inflammed but it looks sunken with opaque drainage on the lower lid.
he is squinting & squints with light response.
his eye is swollen shut, and the tissue around it is swollen
Besides the localized swelling of the surrounding tissue, the most likely injury what is called a traumatic uveitis. This is an irritation to the blood supply to multiple structures within the eye. This is most likely why he is squinting and he is most likely painful as well. I would definitely recommend that you have his eye examined as soon as possible as other more serious conditions have been known to occur following this type of injury including global rupture or retinal detachment that can lead to blindness.
If a uveitis is the diagnosis, he will need treatment with topical steroids and atropine (to dilate the pupil so as not to get adhesions to the lens as well as oral steroids or non-steroidal anti-inflammatories.
In doing some research it appears because a tennis ball is flexible it continues to travel inward after contacting the bony eye socket and will often do more injury to the globe than a hard baseball. For that reason, I would not wait too long to have him examined. Good luck and please let me know if you have any further questions.
Is there anything I can do before I get him to the vet? Cold compress?