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

Differences in adaptation of tonic accommodation with refractive state.

N A McBrien1, M Millodot

  • 1Department of Optometry, University of Wales Institute of Science and Technology, Cardiff, United Kingdom.

Investigative Ophthalmology & Visual Science
|March 1, 1988
PubMed
Summary

Late onset myopes exhibit sustained myopic shifts in tonic accommodation after near work, unlike hyperopes who show transient changes. These refractive group differences suggest autonomic innervation variations may influence accommodation adaptation.

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

Corneal sensitivity in albinos.

Journal of pediatric ophthalmology and strabismus·2014
Same author

Which neurotransmitters modulate corneal sensitivity?

Clinical & experimental optometry·2013
Same author

Expression of muscarinic receptor subtypes in tree shrew ocular tissues and their regulation during the development of myopia.

Molecular vision·2009
Same author

The development of the refractive state in the newborn Thomson gazelle.

Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology·2004
Same author

The role of visual information in the control of scleral matrix biology in myopia.

Current eye research·2002
Same author

Retinal acetylcholine content in normal and myopic eyes: a role in ocular growth control?

Visual neuroscience·2002

Area of Science:

  • Ophthalmology
  • Optometry
  • Physiological Optics

Background:

  • Intersubject variations in tonic accommodation (dark focus) correlate with refractive state.
  • Understanding how sustained visual tasks affect accommodation is crucial for visual health.

Purpose of the Study:

  • To investigate the impact of sustained visual tasks on tonic accommodation levels across different refractive groups (hyperopes, emmetropes, early-onset myopes, late-onset myopes).
  • To assess the decay rate of task-induced changes in tonic accommodation.

Main Methods:

  • Objective infrared optometry (Canon Autoref R-1) measured tonic accommodation before and after a 15-minute sustained visual counting task.
  • Measurements were taken at various distances (6m, pre-task tonic position, 37cm, 20cm).
  • Post-task accommodation levels were monitored for 15 minutes to evaluate decay rates.

Related Experiment Videos

Main Results:

  • Late-onset myopes displayed significant, persistent myopic shifts in tonic accommodation after near work, with no decay.
  • Hyperopes showed transient, counteradaptive decreases in tonic accommodation following sustained near viewing.
  • Emmetropes and early-onset myopes exhibited minimal changes in tonic accommodation at near distances.

Conclusions:

  • Refractive groups differ in their tonic accommodation adaptation to sustained visual tasks.
  • Observed adaptive differences may stem from variations in autonomic innervation of the ciliary muscle.
  • Findings highlight distinct accommodative responses based on refractive error and onset.