Photorefraction with a catadioptric lens. Improvement on the method of Kaakinen

Acta Ophthalmol (Copenh). 1986 Aug;64(4):379-85. doi: 10.1111/j.1755-3768.1986.tb06939.x.

Abstract

Kaakinen (1979) presented a method of measuring refractive error and ocular alignment by simultaneous photography of corneal and fundus reflexes. As presented, the technique was unable to detect refractive errors of less than 2-3 diopters (Howland 1980; Kaakinen 1979). We demonstrate that the use of a catadioptric lens and a long working distance can improve sensitivity to less than 1.0 D. Refractions of a model eye, an accommodating eye and ametropic eyes indicate that refractive errors greater than 0.75 D are readily detectable. The improvement in sensitivity achieved by the present system is attributable to a reduction of the angle between the flash source and the entrance pupil of the photorefractor.

MeSH terms

  • Accommodation, Ocular
  • Adolescent
  • Adult
  • Aged
  • Child
  • Child, Preschool
  • Humans
  • Infant
  • Lenses*
  • Middle Aged
  • Photography
  • Refraction, Ocular
  • Refractive Errors / diagnosis*
  • Vision Tests / methods*