Effect of magnification and field of view on reading speed using a CCTV

Ophthalmic Physiol Opt. 1988;8(2):139-45. doi: 10.1111/j.1475-1313.1988.tb01029.x.


Reading speeds were measured in 18 subjects with normal vision and 10 with low vision for each of 20 experimental conditions with different magnifications and field sizes on the Closed Circuit Television System (CCTV). There was a significant difference between the results for the two groups of subjects. These results suggested that in low-vision patients with faster reading speeds, minimum magnification for maximum field size on the CCTV would be valid advice. For low-vision patients who read more slowly, reading speed may improve at higher magnifications despite reduced field size.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Humans
  • Middle Aged
  • Reading*
  • Sensory Aids*
  • Television*
  • Time Factors
  • Vision, Low / physiopathology