Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Focusing of Light in the Eye

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...

Angle Closure Glaucoma: Treatment

Angle Closure Glaucoma: Treatment

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...

Open Angle Glaucoma: Treatment

Open Angle Glaucoma: Treatment

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...

$Influence of Earth's Curvature and Atmospheric Refraction on Leveling$ 01:26

Influence of Earth's Curvature and Atmospheric Refraction on Leveling

During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...

You might also read

Related Articles

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

Sort by

Same author

CT-defined orbital wall burden and early visual dysfunction in acute orbital.

Emergency radiology·2026

Same author

Heterozygous Pyrin (MEFV) E148Q allele carriers indicate a reduced glaucoma risk for Turkish population: a prospective clinical analysis.

Ophthalmic genetics·2024

Same author

Is single-stage two-muscle surgery of 7-11 mm enough for large-angle exotropia?

International ophthalmology·2022

Same author

Glutathione S-transferase expression in benign and malignant eyelid tumors.

Biotechnic & histochemistry : official publication of the Biological Stain Commission·2021

Same author

Ex-PRESS implantation for different types of glaucoma.

International journal of ophthalmology·2019

Same author

A comparison of two conjunctival rotation autograft techniques in primary pterygium surgery.

Arquivos brasileiros de oftalmologia·2017

Search research articles

Related Experiment Video

Updated: May 9, 2026

$Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter$

Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter

Published on: September 16, 2025

Effect of accommodation on corneal topography.

Hüseyin Bayramlar¹, Fariz Sadigov, Aydn Yildirim

¹Department of Ophthalmology, Istanbul Medeniyet University Medical Faculty, Umraniye, Istanbul, Turkey. hbayramlar@yahoo.com

|July 13, 2013

Summary

Accommodation does not alter corneal topography or cause significant eye cyclotorsion in healthy individuals. This study found no changes in corneal curvature or rotational movement during near focus.

More Related Videos

Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile

Published on: September 20, 2024

Related Experiment Videos

Last Updated: May 9, 2026

$Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter$

Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter

Published on: September 16, 2025

Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile

Published on: September 20, 2024

Area of Science:

Ophthalmology
Optometry
Corneal Science

Background:

Accommodation is the eye's ability to change focus from distant to near objects.
Understanding how accommodation affects ocular structures is crucial for refractive error management.
Corneal topography and ocular cyclotorsion are key parameters in visual optics.

Purpose of the Study:

To investigate the impact of accommodation on corneal topography in healthy subjects.
To determine if the cornea changes curvature during the accommodative process.
To assess the degree of ocular cyclotorsion induced by accommodation.

Main Methods:

Corneal topographic images, iris images, and refraction were obtained using a Nidek OPD-Scan ARK-10000.
Iris landmarks were used to measure ocular cyclotorsion before and during near target fixation.
18 eyes from 10 healthy subjects were analyzed for changes during accommodation.

Main Results:

No apparent difference in corneal topography was observed during accommodation.
No statistically significant difference was found in mean keratometry (P = 0.26).
No significant ocular cyclotorsion was detected during accommodation (P = 0.74).

Conclusions:

The cornea does not change its curvature during accommodation.
Significant ocular cyclotorsion does not occur during the accommodative response.
These findings suggest accommodation primarily involves lens changes, not corneal alterations.