Many people tend to experience dry mouth and eyes at night. Some of the typical signs of this condition include burning, itchy, and gritty eyes, sudden blurred vision, and dryness of mouth which makes swallowing, chewing, and speaking difficult. Some patients often show symptoms like redness of the eyes, light sensitivity, and eye fatigue. In a few cases, patients complain of burning sensation on the tongue, alteration in taste sensation, ulceration of the tongue, etc.