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

Convergence demands by spectacle magnifiers

M Katz1

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

Optometry and Vision Science : Official Publication of the American Academy of Optometry
|August 1, 1996
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

Striatal metabolic rate and clinical response to neuroleptics in schizophrenia.

Archives of general psychiatry·1992
Same author

Frontostriatal disorder of cerebral metabolism in never-medicated schizophrenics.

Archives of general psychiatry·1992
Same author

Malnutrition and immunity.

The Journal of infectious diseases·1992
Same author

Families of children with mental retardation: comprehensive view from an epidemiologic perspective.

American journal of mental retardation : AJMR·1992
Same author

Iniencephaly. A case report.

The Journal of reproductive medicine·1992
Same author

Intracellular proteolysis of pancreatic zymogens.

The Yale journal of biology and medicine·1992
Same journal

Comparison of neutralization and disinfection kinetics in povidone iodine- and hydrogen peroxide-based soft contact lens care solutions.

Optometry and vision science : official publication of the American Academy of Optometry·2026
Same journal

Agreement between ganglion cell-inner plexiform layer metrics from widefield optical coherence tomography and Goldmann II, III, and V in glaucoma.

Optometry and vision science : official publication of the American Academy of Optometry·2026
Same journal

Repeatability of SpotChecks contrast sensitivity test in macular disease.

Optometry and vision science : official publication of the American Academy of Optometry·2026
Same journal

Reflections on emerging therapies for inherited retinal diseases following a community education event: A qualitative exploration.

Optometry and vision science : official publication of the American Academy of Optometry·2026
Same journal

Optical myopia control interventions: Evaluation of methods and success in a real-world population.

Optometry and vision science : official publication of the American Academy of Optometry·2026
Same journal

Influence of corneal endothelial cell density after penetrating keratoplasty on contact lens induced corneal swelling.

Optometry and vision science : official publication of the American Academy of Optometry·2026
See all related articles

This study presents a general equation for spectacle magnifier convergence demands. It highlights the importance of lens optical center separation (s) over base-in prism for accurate calculations.

Area of Science:

  • Optometry
  • Ophthalmology
  • Visual Optics

Background:

  • Spectacle magnifiers are used to aid vision, but their impact on binocular vision demands is complex.
  • Existing methods for calculating convergence demands may be unreliable, especially for virtual images at finite distances.
  • Accurate assessment of visual demands is crucial for patient adaptation to optical aids.

Purpose of the Study:

  • To present a general equation for calculating binocular convergence demands imposed by spectacle magnifiers.
  • To clarify the roles of accommodative demand and base-in prism in these calculations.
  • To identify the most critical parameters for accurate magnifiers' specifications.

Main Methods:

  • Development of a general equation: c delta = k1b + k2sF, where c delta is convergence demand, k1 relates to accommodation, k2 to prism, b is interpupillary distance, s is lens optical center separation, and F is lens power.

Related Experiment Videos

  • Analysis of magnifiers forming virtual images at finite distances (e.g., 25 cm).
  • Analysis of magnifiers forming images at infinity (angular magnification M = F/4).

    • Main Results:

    • The equation c delta = k1b + k2sF accurately predicts convergence demands for various viewing distances.
    • Lens optical center separation (s) is identified as a fundamental and crucial parameter for vendors to specify, more so than base-in prism.
    • When images are formed at infinity, convergence demand simplifies to c delta = sF, independent of interpupillary distance (b) and eye-lens separation (d).

    Conclusions:

    • The proposed equation provides a reliable method for calculating spectacle magnifier convergence demands.
    • Specifying lens optical center separation (s) is essential for accurate optical design and reliable performance.
    • Understanding convergence and accommodation demands aids practitioners in evaluating patient adaptation to spectacle magnifiers.