###Human: My right eye pupil neither dilates or constricts. Why? ###Assistant: Hello. I understand your concerns and have seen your photo attachment (attachment removed to protect patient identity). From the image you have attached, I can say that this may be a persistent pupillary membrane. It is a disorder of eye development that occurs during embryonic growth and development. A condition such as this is usually asymptomatic except for the appearance, but if thick can obstruct vision. There are various treatment options, including laser iridotomy which can be done as an outpatient procedure, which will change the appearance. In case you need further information, please let me know.