I have pain in my right eye when i rub it is this likely caused by a cavity spreading to the eye or something else. is it life threatening? i am 22?

A dental cavity cannot spread to the eye. Eye pain is not normal. Try over the counter artificial tears, but if this is not helpful, see an ophthalmologist ASAP. Pain in the eye has many possible causes, including some, like glaucoma, that can cause vision loss. A dental infection that got into your bloodstream, in theory, could cause sepsis that is life threatening but not likely if you feel ok.