Eyeball is a protective bony structure covered with muscle, connective tissue, and fat. The eyeball moves in all directions of the visual field with the support of extra-ocular muscles. Normally, the movements of both eyes are coordinated, and the brain receives a single image.The eyelids are smooth, striped muscles covered by thin skin, which protects the anterior part of the eye. The eyelids contain several glands. The surface of the cornea and conjunctiva in each arm closure of the eyelids is washed with tears. Tears are vital for maintaining eye health and are made in the lacrimal glands. Tears are shed in response to reflex stimuli or emotional issues. A healthy tear consists of three layers of fat, water and mucus. These layers nourish the cornea and create a smooth surface on the cornea. If there is a defect in any of the layers, the health and integrity of the cornea will be compromised. The conjunctiva is a thin, transparent mucous membrane that act as a protective barrier to the eye against the external stimuli.