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contact lensOphthalmology Crystalline ocular lens A transparent soft or rigid device placed directly on the cornea to correct refractory errors
con·tact lens(kon'takt lenz)
contact lensAn optical correction worn in contact with the cornea and taking the place of spectacles. Most contact lens wearers are shortsighted (myopic) and enjoy a generally better standard of vision than with glasses. Hard contact lenses are made of acrylic PMMA (poly-methyl-methacrylate or ‘Perspex’) or CAB (cellulose acetate-butyrate) or co-polymers of various plastics. Soft lenses are mostly made of HEMA (hydroxy-ethyl-methacrylate). Hard lenses are always of smaller diameter than the cornea, soft lenses are usually of greater diameter.
Patient discussion about contact lens
Q. Contact lenses I’m 17 years old girl, and I have glasses since third grade. I never had any real problems with wearing them,. my best friend always encourage me to try contact lenses, but it seems so strange to put something on directly on your eyes- is it safe? How difficult is it to do?
Q. My contact lenses get very dry and it hurts. any suggestions?
Meanwhile, you may read more here:http://www.nlm.nih.gov/medlineplus/eyewear.html