Related Experiment Video
Updated: Jun 5, 2025
05:10
Measuring the Behavioral Effects of Intraocular Scatter
Published on: February 18, 2021
3.3K
Interactions Between High-Intensity Light and Unrestricted Vision in the Drive for Hyperopia
Sayantan Biswas1,2, Joanna Marie Fianza Busoy1, Veluchamy A Barathi1,3,4
1Singapore Eye Research Institute, Singapore, Singapore.
Investigative Ophthalmology & Visual Science
|December 10, 2024
Summary
Unrestricted vision (UnV) reduces lens-induced hyperopia (LIH) in chicks, while high-intensity light (HL) potentiates it. UnV generally overpowers HL, but prolonged HL exposure can impact emmetropization.
Area of Science:
- Ophthalmology
- Developmental Biology
- Vision Science
Background:
- Lens-induced hyperopia (LIH) is a model for studying refractive error development.
- Understanding factors influencing LIH is crucial for myopia control strategies.
- Chick eyes offer a well-established model for visual development research.
Purpose of the Study:
- To investigate the effects of optical factors versus illuminance on lens-induced hyperopia (LIH).
- To determine the duration-dependency of these factors on LIH.
- To evaluate the interplay between unrestricted vision (UnV) and high-intensity light (HL) in modulating LIH.
Main Methods:
- Hyperopia was induced in chick eyes using +10-diopter lenses from day 1 to day 8 post-hatching.
- Experimental groups were exposed to varying durations (2, 4, 6 hours) of UnV, HL (15,000 lux), or both.
- Ocular axial length, refractive error, and choroidal thickness were measured, with fellow eyes serving as controls.
Main Results:
- LIH induced significant axial shortening, hyperopic shift, and choroidal thickening by day 8.
- UnV exposure dose-dependently reduced LIH development.
- HL exposure dose-dependently potentiated LIH development.
Conclusions:
- Both UnV and HL exposure alter LIH in a duration-dependent manner, presenting competing signals.
- In combined exposure, UnV's effect generally dominates HL, except at 6 hours where HL + UnV resulted in shorter axial length.
- Prolonged HL exposure can influence the emmetropization drive in eyes exposed to UnV.
Related Concept Videos
01:16Focusing of Light in the Eye
2.5K
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...
2.5K
01:22Photoreceptors and Visual Pathways
5.7K
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,...
5.7K
01:27Open Angle Glaucoma: Treatment
391
In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow.
Drugs such as carbonic anhydrase inhibitors, α2- and...
Drugs such as carbonic anhydrase inhibitors, α2- and...
391
01:25Glaucoma: Overview
507
Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal...
507
01:28Angle Closure Glaucoma: Treatment
436
Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor...
436
01:24Color Vision
494
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.
494