Older children and adults can get double vision or see overlapped images if their eyes are not straight. Some retinal problems and rarely cataracts can cause double vision even with straight eyes. Double vision, or diplopia, can be debilitating leading to headaches and eye strain or fatigue. Many patients squint or patch an eye for relief. No matter the age, this can be treated by using prism glasses, getting medicine injected into the eye muscles, and/or having eye muscle surgery.