Temple pain and blurred vision with headaches for 16 days. Hot compress feels good makes vision much worse. Why?

Heat slows nerves. Please get an eye exam if not done already. Tough to answer not knowing the cause of the headaches. But if the blurred vision is due to a problem with your optic nerve behind the eye, then applying heat would make vision worse because heat slows down nerve signals. So please see your doctor to make sure you do not have a condition called optic neuritis.