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

Photoreceptors and Visual Pathways01:22

Photoreceptors and Visual Pathways

At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category, whereas...
Vision01:24

Vision

Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.
Visual Agnosia01:12

Visual Agnosia

Visual agnosia is a condition characterized by the inability to recognize visually presented objects despite having normal vision. For instance, a person with visual agnosia can describe the shape and color of an object but cannot identify or name it. This impairment does not affect their visual field, acuity, color vision, brightness discrimination, language, or memory. An example of this condition in a social setting is someone at a dinner party asking for "that silver thing with a round end"...
Focusing of Light in the Eye01:16

Focusing of Light in the Eye

Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
Visual System01:26

Visual System

Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision.
Once through the pupil, the light passes through the lens, a...
Color Vision01:24

Color Vision

Color perception begins in the retina, the light-sensitive layer at the back of the eye. Two main theories explain how colors are seen: the trichromatic theory and the opponent-process theory. The trichromatic theory, proposed by Thomas Young in 1802 and extended by Hermann von Helmholtz in 1852, suggests that color vision is based on three types of cone receptors in the retina. These cones are sensitive to different but overlapping ranges of wavelengths corresponding to red, blue, and green.

You might also read

Related Articles

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

Sort by
Same author

Contact Lenses.

Canadian Medical Association journal·2010
Same author

18th annual Frank Costenbader Lecture. Fusion and suppression: development and loss.

Journal of pediatric ophthalmology and strabismus·1992
Same author

Results of surgery to modify the null-zone position in congenital nystagmus.

Canadian journal of ophthalmology. Journal canadien d'ophtalmologie·1991
Same author

Unilateral congenital cataract: binocular status after treatment.

Journal of pediatric ophthalmology and strabismus·1989
Same author

Intractable diplopia after vision restoration in unilateral cataract.

American journal of ophthalmology·1989
Same author

Complicated strabismus and adjustable sutures.

Australian and New Zealand journal of ophthalmology·1988
Same journal

Impact of virtual case conferences between primary care clinicians and an interdisciplinary chronic pain clinic.

Canadian family physician Medecin de famille canadien·2026
Same journal

Canadian family physician Medecin de famille canadien·2026
Same journal

Predictors of high-performing family medicine clinics: Prospective cohort study in Alberta.

Canadian family physician Medecin de famille canadien·2026
Same journal

Acetylsalicylic acid use for artial fibrillation and bleeding risk.

Canadian family physician Medecin de famille canadien·2026
Same journal

Clinical practice guidelines: Important tools to teach the art of medicine.

Canadian family physician Medecin de famille canadien·2026
Same journal

Paratonia in advanced dementia: Challenges and evidence-based interventions.

Canadian family physician Medecin de famille canadien·2026
See all related articles

Related Experiment Video

Updated: Jun 4, 2026

A Method to Quantify Visual Information Processing in Children Using Eye Tracking
09:47

A Method to Quantify Visual Information Processing in Children Using Eye Tracking

Published on: July 9, 2016

Visual problems in children.

J A Pratt-Johnson

    Canadian Family Physician Medecin De Famille Canadien
    |February 10, 2011
    PubMed
    Summary
    This summary is machine-generated.

    Early diagnosis of childhood visual problems, like cataracts and strabismus, is crucial for preventing permanent vision loss. Prompt referral and simple tests can identify serious conditions, ensuring timely treatment and preserving sight.

    More Related Videos

    An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System
    05:10

    An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System

    Published on: March 17, 2023

    Portable Intermodal Preferential Looking (IPL): Investigating Language Comprehension in Typically Developing Toddlers and Young Children with Autism
    10:11

    Portable Intermodal Preferential Looking (IPL): Investigating Language Comprehension in Typically Developing Toddlers and Young Children with Autism

    Published on: December 14, 2012

    Related Experiment Videos

    Last Updated: Jun 4, 2026

    A Method to Quantify Visual Information Processing in Children Using Eye Tracking
    09:47

    A Method to Quantify Visual Information Processing in Children Using Eye Tracking

    Published on: July 9, 2016

    An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System
    05:10

    An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System

    Published on: March 17, 2023

    Portable Intermodal Preferential Looking (IPL): Investigating Language Comprehension in Typically Developing Toddlers and Young Children with Autism
    10:11

    Portable Intermodal Preferential Looking (IPL): Investigating Language Comprehension in Typically Developing Toddlers and Young Children with Autism

    Published on: December 14, 2012

    Area of Science:

    • Ophthalmology
    • Pediatric Optometry
    • Developmental Pediatrics

    Background:

    • Early diagnosis of visual impairments in children is critical for preventing irreversible vision loss.
    • Conditions like deprivation amblyopia (due to cataracts) and strabismic amblyopia require immediate attention.
    • Delayed diagnosis can lead to permanently arrested visual development.

    Purpose of the Study:

    • To highlight the urgency of diagnosing visual problems in young children.
    • To emphasize the role of early detection in preventing amblyopia.
    • To introduce practical diagnostic methods for differentiating visual issues.

    Main Methods:

    • Description of the simple pinhole test for vision assessment.
    • Discussion of diagnostic criteria for congenital nystagmus.
    • Consideration of primary reading difficulties (dyslexia) in relation to visual health.

    Main Results:

    • The pinhole test effectively distinguishes refractive errors from serious organic causes of poor vision.
    • Acquired convergent strabismus leading to amblyopia is preventable with early referral.
    • Congenital nystagmus and dyslexia require specific diagnostic considerations.

    Conclusions:

    • Prompt diagnosis and referral are essential for managing childhood visual impairments.
    • Preventable conditions like strabismic amblyopia underscore the need for timely intervention.
    • The pinhole test offers a practical tool for initial vision screening in children.