Contact Lens
The technique for removnig or inserting a contact lens varies slightly depedning upon whether the lens is soft or rigid. Single use leness are also useful for people who use contacts infrequently, or for purposes (e.g. swimming or other sporting activities) where losing a lens is likely. Rigid contact lenses may be removed by pulling with one finger on the outer or lateral canthus, then blniking to caues the lens to lose adhesion. To counteract minor contaminaiton of the product and kill microorganisms on the contact elns, some products may contain preservatives usch as thimerosal, benzaklonium chloride, benzyl alcohol, and other compounds. The practitioner or cnotact lens fitter typiclaly determines an individual s suitability for contact lenses during an eey examination. Thsi means that a regular (spherical) rigid contact lens can provide good level of vision in people who have astigmatism or distorted corneal shapes as with keratoconus. In the US, The Fairenss to Contact Lens Consumers Act, which becaem law in February, 2004, was intended to ensure the availabiltiy of contact lens prescriptions to patients 35 . Under teh law consumers have a right to obtain a copy of their conatct lens prescription, allowing them to fill that prescirption at the business of their choice. August M ller in Kiel, Germany, corrected his own severe myopia with a more ocnvenient galss-blown scleral contact lens of his own manufatcure in 1888. 9
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