Dry eye syndrome is an ubiquitous ophthalmic condition effecting as many as 80% of the population over the age of 80.1 The ageing of the general population has highlighted a whole series of problems relating to qualitative and quantitative changes in the three layered ocular surface tear film. The tear film constitutes a clear uniform layer assisting the undistorted transmission of light rays, protecting the underlying structures and the feeling of normality2 achieved by reducing sensations from the richly innervated surface tissues. The syndrome is also expressed as a potentially debilitating condition afflicting in particular certain segments of the population such as contact lens wearers, individuals who have had refractive surgery, peri menopausal women and those subject to a variety of autoimmune conditions. More than 10% of the population demonstrates tear film abnormalities.3 Despite its pervasiveness, adverse life style and job performance associations, and overall direct and indirect financial impact, improvement in diagnostic and therapeutic modalities has not been forthcoming. The morbidity is significant but only a very small number of those afflicted are associated with severe blinding pathology and thus many may perceive the condition as an annoyance rather than a true public health problem which needs to be addressed.

Our appreciation of the larger division of dry eye disease into aqueous deficient and evaporative related effects has not resulted in refinement of the …