Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Temporal constraints on lens compensation in chicks.

Jonathan Winawer1, Josh Wallman

  • 1The City College of The City University of New York, New York, NY 10031, USA. winawer@mit.edu

Vision Research
|November 26, 2002
PubMed
Summary

The chick eye compensates for spectacle lens-induced defocus through altered growth, with brief, intermittent visual exposure being most effective. Specific visual patterns, not just total duration, influence ocular compensation mechanisms like scleral and choroidal changes.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Normalization accounts for temporal dynamics in human somatosensory cortex.

bioRxiv : the preprint server for biology·2026
Same author

An increasingly efficient narrowband object-recognition channel along the ventral stream.

bioRxiv : the preprint server for biology·2026
Same author

EasyEyes: Crowded dynamic fixation for online psychophysics.

Journal of vision·2026
Same author

A case study of sudden-onset cortically mediated visual impairments in a 12-year-old.

Research square·2025
Same author

Unpacking the V1 map: Differential covariation of preferred spatial frequency and cortical magnification across spatial dimensions.

PLoS computational biology·2025
Same author

Spatial attention selectively alters visual cortical representation during target anticipation.

Nature communications·2025

Area of Science:

  • Ophthalmology
  • Developmental Biology
  • Animal Models

Background:

  • Emmetropization is the process by which the eye maintains focus during growth.
  • Spectacle lenses can alter the eye's effective focal length, potentially disrupting emmetropization.
  • Understanding the visual stimuli required for ocular compensation is crucial for managing refractive development.

Purpose of the Study:

  • To investigate the visual exposure requirements for ocular compensation in a chick model.
  • To determine the specific visual patterns that trigger scleral and choroidal compensatory mechanisms.
  • To explore the non-linear nature of the emmetropization system's response to visual feedback.

Main Methods:

  • Chicks were exposed to spectacle lenses (plus and minus) under controlled visual conditions.

Related Experiment Videos

  • Ocular compensation was assessed by measuring the rate of ocular elongation (scleral mechanism) and choroidal thickness.
  • Experimental conditions manipulated the duration, frequency, and sequence of lens wear.

    • Main Results:

    • Surprisingly small amounts of vision through spectacle lenses induced robust scleral and choroidal compensation.
    • Intermittent, brief daily visual episodes were more effective than continuous or infrequent long episodes.
    • The effect of plus lenses dominated over minus lenses when worn successively.
    • Elongation and choroidal responses were dissociable, with plus lenses primarily affecting elongation and minus lenses affecting choroid.

    Conclusions:

    • The emmetropization system does not integrate visual defocus linearly.
    • Specific temporal patterns of visual exposure, rather than total duration, are critical for ocular compensation.
    • These findings may explain the complex relationship between nearwork and myopia development in children.