05/01/2026
Dry eyes occur when the eyes either don’t make enough tears, or the quality of the tears produced is reduced, which means the tears can evaporate rapidly from the surface of the eye, causing the eye to dry out. Often, the reduced tear quality is a result of blockage or inflammation of the oil glands within the lid margin. When the surface of the eyes dries out, they become inflamed. They appear red, and the whites of the eyes can appear to be pink and swollen. Normally, the eyes become very irritable. When seen on the microscope, using a fluorescent dye called fluorescein and a special cobalt blue light, the denuded surface areas can be seen as green specks on the surface of the eye.
If the main problem is a lack of tear production, then the term ‘keratoconjunctivitis sicca’ or ‘aqueous deficiency’ is used. However, if the main problem is poor tear quality (but plenty of them) as a result of inflammation or blockage of the oil-secreting glands in the lid margin, then the condition is called ‘obstructive meibomian gland disease’, more commonly referred to as blepharitis.
