When i lay down and watch tv or use my ipod for a while, i start to see the words double like if i had diplopia. vertically, i see 2 of the same words?

Double vision: Some people confuse double vision and blurred vision. Double vision is seeing two distinct, separate images of the same thing. Most double vision is due to misalignment of the eyes. Double vision with fatigue is common in people who have a tendency for misalignment - called a phoria. If it occurs frequent, a correction in glasses called prism can done to reduce or eliminate it.