Ever since I was a teenager, my left pupil dilates really big, I am now 32 years old. It does it at random times
for no reason, or when I drink alcohol, take OTC medicines, and with my anxiety medicine, Pristiq. It blurs my vision and makes it hard to see out of when it dilates and sometimes causes my headaches. I have an astigmatism in my left eye, as well. I went to an eye doctor and had a thorough check up. He sent me to get a cat scan done and they didn't come up with anything.