Jacqui Mayhew 

Contact lenses for dry eyes  worn only while sleeping offer a unique new solution to the increasing numbers of daytime contact lens wearers who find that winter usually leads to increased problems with dry irritable eyes and blurred vision. Winter weather gives rise to greater dry eye problems because the colder air cannot hold as much water vapour as warmer air so there is less humidity and accordingly there is an increased tendency for liquid water to evaporate into the atmosphere. Whilst this is readily noticed in the ways that water collecting in puddles seems to disappear quickly, it also applies to the tear film in people's eyes given it is 98% water hence the greater risk of dry eye during the winter.

This outdoor problem is exacerbated by various other ‘lifestyle' factors - working in low humidity air-conditioned offices, spending too long staring at computer screens, smartphones and TVs - and by late afternoon many daytime contact lens wearers are suffering badly with comfort and vision issues. This is where the new ortho-k contact lenses for dry eyes  offer a solution since these small custom-designed lenses are only worn overnight and not at all during daytime. The lenses correct short-sightedness by gently flattening the surface of the eyes under the mild pressure of closed eyelids during sleep. This flattening effect lasts for over 24 hours and ensures light entering the eyes focuses directly on the retina at the back of the eye and not in front of it.

When the lenses are removed each morning, the wearer enjoys perfect natural daytime vision all day long until reinserting the lenses at night. So there is no risk of the blurred vision which accompanies winter dry eye. This occurs when the tear film's water content evaporates at too fast a rate leading to the tear gland filling the eyes with reflex tears making them watery and impairing light refraction which then results in blurred vision. Dry eye symptoms increase in winter because more time is spent indoors, in rooms with insulated walls and windows and central heating where low humidity air continually takes moisture from the eyes. So ortho-k contact lenses for dry eyes  offer a new way for daytime contact lens wearers to avoid winter discomfort and blurred vision.