I am not 100% certain, but this is what I think As you probably know with Graves' disease, the muscles that control the eyeglobe are affected and a lot of times can cause restriction of the muscles within the eye socket, and at times causing the eye to protrude. I don't know at what stage of Graves' you have. I think that when you blew your nose, you may have produced a pressure to go up toward the globe and caused some compression on the muscle (that connects to the eyeball), thus creating this stars (phosphenes). I don't think there is anything dangerous about that. However, if this happens whether you blow your nose or not, it may be best to see an ophthalmologist to rule out anything within the eye. Just curious, do you remember in what area these stars appeared when that happened?As for the red eye you suffer, unfortunately it is a very common symptom of Graves. Be sure you have artificial tears handy during the day or ointment for night time. Severe dry eye can increase your risk for conjunctivitis. Keep your sunglasses on while you are out and about (if you don't wear glasses already). It is best to manage this with an optometrist or ophthalmologist so that your daily life is not affected.Hope you get all sorted out soon. Take care.