enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Prentice position - Wikipedia

    en.wikipedia.org/wiki/Prentice_position

    The Prentice position is an orientation of a prism, used in optics, optometry and ophthalmology. In this position, named after the optician Charles F. Prentice, the prism is oriented such that light enters it at an angle of 90° to the first surface, so that the beam does not refract at that surface. All the deviation caused by the prism takes ...

  3. Eye chart - Wikipedia

    en.wikipedia.org/wiki/Eye_chart

    An eye chart is a chart used to measure visual acuity comprising lines of optotypes in ranges of sizes. Optotypes are the letters or symbols shown on an eye chart. Eye charts are often used by health care professionals, such as optometrists, physicians and nurses, to screen persons for vision impairment.