Hi, One of the most common causes of eye fatigue is staring for long periods at digital devices such as: Computer screens, Smartphones, Reading, Writing, Driving. Sometimes eye fatigue is a sign of an underlying condition that may need medical treatment. If eye fatigue persists despite taking simple precautions, see your doctor. Especially if your eye fatigue is associated with headache or with eye problems such as: Discomfort, Double vision, Significant change in vision. This type of eye fatigue or eye strain is sometimes known as computer vision syndrome. It affects about 50%-90% of computer workers.  Kindly consult Ophthalmologist...