Err on the side of caution.

One of my yoga students has glaucoma in one eye. He went to the doctor and they gave him eye drops and his eye pressure drastically went down and a blood vessel exploded and filled the eyeball with blood.  Right now he is "temporarily" blind in that eye.  He asked if I thought it might help if he were to apply a warm, wet towel on the eye.  I told him that he should ask his doctor about that.

As yoga teachers we should know our limitations when it comes to therapeutic practices and recommendations. As you probably know, there are different levels of knowledge and skill when it comes to yoga teaching.  Yoga Alliance ( https://www.yogaalliance.org/ ) has various levels of registered yoga teacher (RYT) such as RYT-200, RYT-500, ERYT-200, and so on.  They even have a registered therapy yoga teacher. Even if you are a therapy yoga teacher there are limitations in what you should do as far helping students.

If it is beyond your knowledge it is best to always err on the side of caution and recommend they go see a specialist.  Never let your ego get in the way of good judgement.  That's my recommendation.