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

Tonic accommodation, tonic vergence and surround propinquity

N N Chiu1, M Rosenfield

  • 1Department of Vision Sciences, State University of New York, State College of Optometry, NY 10010.

Ophthalmic & Physiological Optics : the Journal of the British College of Ophthalmic Opticians (Optometrists)
|July 1, 1994
PubMed
Summary
This summary is machine-generated.

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

Vergence adaptation in children and its clinical significance.

Binocular vision & strabismus quarterly·2001
Same author

Nearwork distances in children.

Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)·2001
Same author

Effect of near-vision addition lenses on the accuracy of the accommodative response.

Optometry (St. Louis, Mo.)·2001
Same author

Vergence adaptation and the clinical AC/A ratio.

Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)·2000
Same author

Accommodative error, adaptation and myopia.

Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)·2000
Same author

Blur sensitivity in myopes.

Optometry and vision science : official publication of the American Academy of Optometry·1999

Measurements of tonic accommodation (TA) in darkness may overestimate its magnitude. Viewing an illuminated target reduced TA, suggesting surround propinquity influences accommodative responses.

Area of Science:

  • Ophthalmology
  • Vision Science
  • Human Physiology

Background:

  • Tonic accommodation (TA) and tonic vergence (TV) are typically measured in darkness.
  • Surround propinquity, awareness of surroundings, may influence accommodative responses even in dark conditions.

Purpose of the Study:

  • To measure TA and TV while minimizing surround propinquity effects.
  • To compare TA measurements in an illuminated environment versus total darkness.

Main Methods:

  • TA was measured objectively using an infrared optometer with a 0.5 mm pinhole on an illuminated distant target and in darkness.
  • TV was assessed subjectively by measuring heterophoria with subjects viewing a distant target binocularly through pinholes.

Main Results:

Related Experiment Videos

  • Mean TA was significantly lower (0.28 D) with the pinhole technique on an illuminated target compared to darkness (0.60 D).
  • A strong positive correlation (r=0.86) was found between the difference in TA measurements and the level of TA in darkness.
  • Subjects with higher TA in darkness showed a larger propinquity effect.

Conclusions:

  • Measurements of TA in total darkness likely overestimate its magnitude and normal range.
  • Surround propinquity significantly influences tonic accommodation.
  • Tonic vergence showed no significant correlation with tonic accommodation measurements.