The majority of blood-derived eyedrops comes from the patient's own blood. Some come from a compatible donor chosen by the doctor for a patient in particular. These drops cannot be exchanged between patients under any circumstances whatsoever and can only be used by the person for whom the doctor has prescribed them. Anything to the contrary is completely prohibited. If you think autologous serum could work well for you, please consult your ophthalmologist who will assess your status and if suitable will prescribe it for you.