Related Experiment Video
Updated: Sep 4, 2025
07:20
Inducement and Evaluation of a Murine Model of Experimental Myopia
Published on: January 22, 2019
10.0K
Chromatically simulated myopic blur counteracts a myopiagenic environment
Timothy J Gawne1, Zhihui She1, Thomas T Norton1
1Department of Optometry and Vision Science, University of Alabama at Birmingham (UAB), USA.
Experimental Eye Research
|July 17, 2022
Summary
Environmental factors drive myopia. Restricting vision in tree shrews induced myopia, but blue light defocusing reversed this, suggesting chromatic cues are key for myopia control.
Area of Science:
- Ophthalmology
- Animal Models
- Visual Science
Background:
- A global myopia epidemic is linked to environmental visual cues disrupting eye focus.
- Myopic defocus and light wavelength influence myopia progression in children.
Purpose of the Study:
- To investigate if restricted viewing distance induces myopia in tree shrews.
- To determine if chromatic myopic defocus can counteract environmentally-induced myopia.
Main Methods:
- Tree shrews were housed in small cages with restricted viewing distances, some exposed to a video display.
- One group received a blue-channel blurred video display to simulate chromatic myopic defocus.
- Refractive error and axial elongation were measured.
Main Results:
- Tree shrews in restricted environments developed significant myopia (-1.2 D).
- Simulated myopic defocus using blue light blurring induced hyperopia (+4.0 D) due to slowed axial elongation.
- Chromatic cues demonstrated high potency in refractive regulation.
Conclusions:
- Environmental factors, particularly visual cues, significantly impact refractive development.
- Chromatic myopic defocus shows potential as an anti-myopia strategy.
- Tree shrews serve as a viable model for studying myopia and its environmental influences.
Related Concept Videos
01:16Focusing of Light in the Eye
3.2K
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...
3.2K
01:20Anatomy of the Eyeball
7.5K
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle...
7.5K
01:22Photoreceptors and Visual Pathways
6.4K
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,...
6.4K
01:28Angle Closure Glaucoma: Treatment
641
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...
641
01:27Open Angle Glaucoma: Treatment
538
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...
538
01:25Glaucoma: Overview
718
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...
718