If your pet feels pain or uncomfortable, and it is getting bigger, bleeding, or discharged, you should visit a vet soon. Your vet will take care of this with medication, surgical, or squeezing removal, depending on the size, area, and type of it after evaluations.
If your pet does not, and it is not, you can wait for a few days more to check its progression. In that time, you should carefully review the swollen area every day. If you find those symptoms that I mentioned above, you should visit a vet soon. Unfortunately, I am not sure about the reason for swollen because I can not get a chance to evaluate the area. However, many of them were due to inflammation. For the time being, apply ice packs to the swollen area.
Please let us know if you have further questions. Thank you.

Came home at 6pm and he kept closing his eye like something was in it. We washed it out but it began to swell and get red. He’s unable to open his eye all the way.

My dogs left eye is swollen and red