There could be a lot of things that are going on with you. Ask yourself these questions and see if you can't figure it out on your own:
Have you eaten or drank water recently? You could have low blood sugar or be dehydrated.
Have you slept in the last 24 hours?
Does it happen only at specific times (like when you're riding in a car, or looking at a bright light?)
Ultimately, you'll probably want to visit your family doctor. They'll be able to evaluate your condition better than anyone on a site like this.
Have you eaten or drank water recently? You could have low blood sugar or be dehydrated.
Have you slept in the last 24 hours?
Does it happen only at specific times (like when you're riding in a car, or looking at a bright light?)
Ultimately, you'll probably want to visit your family doctor. They'll be able to evaluate your condition better than anyone on a site like this.