By Jacqui Mayhew 

Contact lenses for dry eyes  sufferers which enable them to enjoy great vision without having to resort to wearing glasses represents a major product development challenge for the optical industry. In today's air-conditioned dry atmosphere world, people spend increasing amounts of time staring at screens - computers, TVs, mobile phones - reducing blink rates by around two-thirds and leading to less tear film production which is the normal constant flow of liquid that coats the eye to keep the cornea moist. In the US, almost 60m people are estimated to suffer from some form of dry eye problem according to the Eagle Vision-Yankelovich poll and so it is no surprise that substantial development efforts by major optical and pharmaceutical companies are targeted at solving this problem.

Tears contain a combination of water, mucus and fat. They also contain sugar, protein, and a bacteria-destroying enzyme that protects the eye against infection. When the balance of this system is disturbed then burning, itching and a scratchy or sandy sensation usually are the result. For optical pharma companies, the development focus is on drug-based therapies - primarily delivered in the form of eye drops - which can enable wearers of conventional contact lenses to mitigate their dry eyes condition. For lens manufacturers, the development focus has been on increasing water content to create contact lenses for dry eyes  sufferers which help to alleviate the problem. Other developments include special eye masks usually worn while sleeping which slow down moisture loss.

However, as the huge number of sufferers indicates, this is a problem where no single solution appears to be consistently successful. In part, this reflects the fact as well as environmental factors which contribute to the development of dry eyes, a range of medical conditions and even unrelated drug treatments for other conditions can have the associated effect of reducing tear film production. Tranquilizers, ant-histamines and decongestants all have this effect to varying degrees. Even simply suffering from a Vitamin A deficiency can be a causal factor. In such circumstances, the option of wearing overnight corrective contact lenses for dry eyes  should be considered since this removes the need for any daytime contact lens wear.

Check if you are suitable for overnight corrective contact lenses