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 Concept Videos

Muscles of the Eye01:20

Muscles of the Eye

The muscles of the eye are sophisticated structures that control eye movement and focus, allowing for the precise and rapid adjustments necessary for vision. The human eye is controlled by ten muscles — six extraocular muscles, three intraocular muscles, and one primary eyelid retractor muscle.
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and rotating...
Accessory Structures of the Eye01:17

Accessory Structures of the Eye

Optical perception, or vision, is an extraordinary sense dependent on converting light signals received via the ocular organs. These organs, known as eyes, are securely positioned within the bony cavities of the skull, called orbits. The orbits serve a dual purpose: a protective shield for the ocular globes and a stable attachment point for the soft ocular tissues. The eye's external protective mechanisms include the eyelids, which are edged with lashes that act as a barrier against foreign...
Fascicle Arrangement in Skeletal Muscles01:25

Fascicle Arrangement in Skeletal Muscles

Fascicles are bundles of muscle fibers in a skeletal muscle. Muscle fascicle arrangement is directly associated with the power and range of motion of various muscles. The configuration of these fascicles can vary, leading to different functional outcomes.
The four primary types of muscle based on fascicle arrangement are:
Muscles for Facial Expressions01:14

Muscles for Facial Expressions

The craniofacial muscles are a collection of approximately 20 thin skeletal muscles situated beneath the skin of the face and scalp. These muscles, primarily responsible for the vast array of human facial expressions, originate from the bones or fibrous structures of the skull and extend outwards to connect with the skin. While most skeletal muscles in the body are enveloped in thick fascia, facial muscles generally have a more delicate fascial covering, with the buccinator muscle being a...
Cranial Nerves: Types Part I01:14

Cranial Nerves: Types Part I

Cranial nerves are responsible for transmitting motor and sensory information between the brain and various parts of the body. There are twelve pairs of cranial nerves, with the first six being essential in sensory perception, motor control, and autonomic functions related to the head and neck.
Olfactory Nerve (Cranial Nerve I)
The olfactory nerve, or cranial nerve I, is unique as it is purely sensory and dedicated to the sense of smell. This nerve originates in the olfactory epithelium of the...
Muscle Coordination and Action01:24

Muscle Coordination and Action

Muscle coordination is a complex and finely tuned process essential for smooth and purposeful movements like flexion, extension, adduction, abduction, and rotation. The human body orchestrates the actions of various muscles working in concert, each with a specific role. Four functional types describe how muscles work together: agonist, antagonist, synergist, and fixator.
Agonists
Agonist muscles, often called prime movers, are the primary muscles responsible for producing a specific movement.

You might also read

Related Articles

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

Sort by
Same author

A multinational randomized clinical trial of an eye-tracking-based binocular amblyopia treatment in children aged 4-9 years.

Scientific reports·2026
Same author

High-Adherence Dichoptic Treatment Versus Patching in Anisometropic and Small Angle Strabismus Amblyopia: A Randomized Controlled Trial.

American journal of ophthalmology·2024
Same author

Lateral Rectus Disabling and Simultaneous Modified Nishida Procedure for Exotropic Duane Retraction Syndrome.

Journal of binocular vision and ocular motility·2024
Same author

Binocular Home Treatment for Amblyopia: Gains Stable for One Year.

American journal of ophthalmology·2024
Same author

Modified Nishida Procedure Combined with Lateral Rectus Disabling for Duane Retraction Syndrome.

Journal of binocular vision and ocular motility·2023
Same author

An Eye-Tracking-Based Dichoptic Home Treatment for Amblyopia: A Multicenter Randomized Clinical Trial.

Ophthalmology·2022

Related Experiment Video

Updated: May 30, 2026

Assessing Binocular Central Visual Field and Binocular Eye Movements in a Dichoptic Viewing Condition
07:45

Assessing Binocular Central Visual Field and Binocular Eye Movements in a Dichoptic Viewing Condition

Published on: July 21, 2020

Incomitant strabismus: does extraocular muscle form denote function?

Burton J Kushner1

  • 1Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin 53705, USA. bkushner@wisc.edu

The American Orthoptic Journal
|August 23, 2011
PubMed
Summary

Extraocular muscle (EOM) overaction or underaction may not stem from size changes. Altered neural input or fiber type shifts in normal-sized EOMs can explain clinical observations.

More Related Videos

Ocular Kinematics Measured by In Vitro Stimulation of the Cranial Nerves in the Turtle
10:49

Ocular Kinematics Measured by In Vitro Stimulation of the Cranial Nerves in the Turtle

Published on: June 2, 2018

Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes
08:27

Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes

Published on: March 3, 2023

Related Experiment Videos

Last Updated: May 30, 2026

Assessing Binocular Central Visual Field and Binocular Eye Movements in a Dichoptic Viewing Condition
07:45

Assessing Binocular Central Visual Field and Binocular Eye Movements in a Dichoptic Viewing Condition

Published on: July 21, 2020

Ocular Kinematics Measured by In Vitro Stimulation of the Cranial Nerves in the Turtle
10:49

Ocular Kinematics Measured by In Vitro Stimulation of the Cranial Nerves in the Turtle

Published on: June 2, 2018

Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes
08:27

Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes

Published on: March 3, 2023

Area of Science:

  • Ophthalmology
  • Neuroscience
  • Muscle Physiology

Background:

  • Traditional understanding links extraocular muscle (EOM) size to function: underacting muscles are atrophic/hypoplastic, overacting ones are enlarged.
  • This paradigm conflicts with clinical findings in conditions like superior oblique palsy and superior rectus overaction/contracture syndrome, where EOMs often have normal diameters.

Discussion:

  • Clinical inconsistencies suggest EOM size may not solely dictate contractile activity.
  • Altered neural input to anatomically normal EOMs could explain functional changes.
  • Changes in muscle fiber type and distribution within a normal-sized EOM might also alter contractile activity.

Key Insights:

  • EOM contractile activity may be modulated by neural input changes, not just muscle size.
  • Fiber type shifts within normal-sized EOMs can mimic functional abnormalities.
  • Vergence adaptation and altered neural stimuli are potential mechanisms for EOM remodeling.

Outlook:

  • Further research into neural control and muscle plasticity is needed.
  • This revised understanding could impact diagnostic approaches and treatment strategies for strabismus and other EOM disorders.