Abstract
A new technique, Infrared Photoretinoscopy, has been employed for recording natural accommodation in the chicken. The illumination of the pupil by the fundus reflection of infrared light provided by high output light emitting diodes (I.R. LED's) was monitored on a video screen. The defocus of the eye could be calculated by evaluating the fraction of the pupil which was illuminated. It was found that: (a) in the chick the full range of accommodation (about 17D) is present in the first day after hatching, (b) accommodation acts completely independently in both eyes, (c) the “near pupillary response” is weaker in younger chicks, (d) the pupil constriction in response to light starts at higher luminance in the younger chicks (e) the developmental decrease of the f/number is not sufficient to explain the change of the pupil reaction to light. Problems resulting from the use of drugs in order to measure the refractive state using normal retinoscopy are discussed.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.