Problems with the vision or seeing double. Of course, a loss of vision could indicate simply that… a loss of vision due to an environment and genetic factors. But you must not take a loss of vision too lightly, as it can sometimes be an indicator of a more serious condition. If it comes on suddenly, and especially if it is concentrated in one eye, you should consult a physician at the earliest. An aneurysm exerting pressure upon the optic nerve can lead to sudden, severe problems with the eyesight, or even result in a person seeing double.