Ocular double vision has little to do with presbyopia. Presbyopia is a condition in which it is difficult to see near objects, making it necessary for the patient to read books and mobile phones at a distance. Because the elderly have reduced eye regulation and cannot read books or newspapers for long periods of time, they are prone to the symptoms of visual fatigue. Ocular double vision, on the other hand, refers to the appearance of double or multiple images when looking at an object, which in turn makes it impossible for the patient to accurately determine the position of the object. It is usually caused by cataracts, astigmatism or extraocular muscle paralysis in the elderly.