It is true that overactive thyroid or hyperthyroidism can affect vision. The hyperthyroid is usually caused by Grave's disease. Stare, eye irritation, bulging of the eyes, double vision and loss of vision can be the symptom of hyperthyroidism on eyes. In some cases, patients suffer from acute angle glaucoma caused by hypothyroidism. Hyperthyroidism has other effects on body, such as jitteriness, shaking, increased nervousness, irritability, palpitation, hot feeling, loss in weight and high frequency of bowel movement. Dryness and scratchy sensation in eyes can also bother the patients. Fortunately, this problem is easy to get rid of by applying topical lubrication. However, the link between thyroid disease and vision problem should be defined by doctors.