BookRags.com Literature Guides Literature
Guides
Criticism & Essays Criticism &
Essays
Questions & Answers Questions &
Answers
Lesson Plans Lesson
Plans
My Bibliography Periodic Table U.S. Presidents Shakespeare Sonnet Shake-Up
Research Anything:        
History | Encyclopedias | Films | News | Create a Bibliography | More... Login | Register | Help


Search "Contact Lens"

Navigation

Contact Lens

Print-Friendly  Order the PDF version  Order the RTF version
About 1 pages (88 words)
Contact lens Summary

Thin artificial lens worn on the surface of the eye to correct refractive defects of vision. Early glass contact lenses, invented in 1887, were uncomfortable and could not be worn long.

Plastic-based lenses, made to measurements of corneal curvature taken by optical instruments, were first developed in the mid 20th century. Gas-permeable lenses allow more oxygen to reach the eye, thus increasing comfort and wear time. Contact lenses have advantages over eyeglasses for certain visual defects and may be preferred for the sake of appearance and other reasons.

This is the complete article, containing 88 words (approx. 1 page at 300 words per page).

View More Summaries on Contact lens
More Information
  • View Contact Lens Study Pack
  • Search Results for "Contact Lens"
  • Add This to Your Bibliography
  • More Products on This Subject
    Caring for Contacts
    Spectacles have been around for centuries. For ages they have been the only tools that assisted the... more

    Contact Lenses
    Contact lenses have become a new trend in the eyewear facade. Perfect vision is very uncommon, thus... more


     
    Copyrights
    Contact Lens from Encyclopedia Brittanica. ©2009 Encyclopedia Brittanica. All rights reserved.

    Join BookRagslearn moreJoin BookRags




    About BookRags | Customer Service | Report an Error | Terms of Use | Privacy Policy