Although the vast majority of contact lenses being dispensed are for correction of straight forward long and shortsightedness, there are other specific situations where more complex designed lenses correct visual faults.

In the case of Astigmatism, where the front of the eye is more rugby ball shaped, Soft Toric lenses are most commonly fitted by the optician. This corrects a specific visual requirement across one part of the eye, be it horizontal, vertical, oblique, etc. The smaller rigid gas permable lenses (RGP) are also used for astigmatism. Although they can be initially uncomfortable, are deemed a healthy option giving good tear exchange, supply of oxygen, are easily cleaned and have a long life.

In mature individuals, when reading becomes an issue (Presbyopia), Multifocal Contact lenses can be used, where approximately one third of the lens in a specialised design is devoted to the reading purpose without compromising the distance element. Such lenses, after a lot of previous design faults, are now being successfully used.

Coloured lenses are widely used for either enhancing the eyes own colour or indeed changing it, with ‘themed’ lenses now more popular on the party scene.

Contact lenses are also used medically within hospitals, where bandage lenses are placed on a diseased or injured cornea, protecting its surface and enabling treatment drug contact for longer. Specifically painted lenses to mimic the eye cosmetically are also used in severe cases.

Noel McCrystal

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

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