People who suffer from migraines are already familiar with the optical signal of seeing "halos." These orb-like spots that either stand still and vibrate or dart about in your field of vision signal an oncoming migraine. Even if you cannot feel a migraine yet, you know it is coming. However, when you see halos and do not experience a migraine following it, and you also experience tunnel vision, you should know that these two vision experiences together are not signs of your imminent death. Here is what they really are.
When you stare at a computer screen all day without much of a break, your eyes lose some ability to adapt to viewing the real world. The more tired your eyes are, the more likely they will cause you to see bright orbs of light. If you do not immediately back away from a viewing screen and rest, the problem progresses to seeing only straight ahead with a limited field of vision, or "tunnel" vision. Proper eye care for this problem is just rest, and preferably more of it.
Seizures are another possibility, but if you have never had a seizure before, it is highly unlikely. Still, a seizure disorder can develop at any time in your life. If this persists, and your vision issues are followed by any type of seizure, see your eye doctor right away. There may be something else going on in your brain that has led you to this particular point. If your doctor or eye doctor orders an MRI, there is a good chance that you will uncover the source of the problem.
Side Effects of Medication
There are many medications that also produce bizarre visual side effects. Most doctors warn you of these issues and request that you contact them if you experience halos and tunnels. They will want to remove you from those medications and try something else for what ails you.
Optic Nerve Problems
Finally, your optic nerves may have some potentially unpleasant health issues. When your optic nerves are affected by tumors or disease, your eye doctor will want to diagnose that sooner rather than later. Your site may be saved if your eye doctor catches these health problems right away. If you ignore the problem, or you think it is caused by something else (e.g., a migraine), the disease or tumor could progress to the point where you are robbed of your sight.