These lenses have a floppy structure as their name suggests, mimicing strong cling film and therefore are very comfortable to wear. They are larger in diameter (approx 14mm) than their rigid counterparts (approx 9mm), covering all of the eyes cornea. This most popular type of lens can be worn on a daily, monthly or extended wear basis.

The daily lens is often used for more occasional wear such as sports and social activities. This single use lens is inserted in the eye for 4-6 hours after which it should be disposed of. As there is no lens cleaning involved, it is the most hygienic of all lens types. A new ‘moist’ version is now available, suitable for those with reduced tear flow.

The monthly lens is suited to those requiring increased wear of 5-7 days per week. This type can be worn up to 10-12 hours per day, but no more.

The lens material which requires nightly cleaning, normally has 58% water content in its structure and needs to be kept well hydrated by sufficient blinking, particularly during times of intense concentration e.g. VDU use.

The use of extended wear lenses (constant for 30 days) has attracted a lot of debate and controversy over the years, where the lack of oxygen and build up of bacteria pose the biggest threat. The advent of new ‘silicon hydrogel’ lenses though apparently over come these issues successfully.

Noel McCrystal

BSc.(Hons.)MCOptom.Dip.Sc.V MASv.P

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