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

Focusing of Light in the Eye01:16

Focusing of Light in the Eye

7.0K
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...
7.0K
Angle Closure Glaucoma: Treatment01:28

Angle Closure Glaucoma: Treatment

1.5K
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...
1.5K
Open Angle Glaucoma: Treatment01:27

Open Angle Glaucoma: Treatment

1.1K
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...
1.1K
Accessory Structures of the Eye01:17

Accessory Structures of the Eye

4.2K
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...
4.2K
Glaucoma: Overview01:25

Glaucoma: Overview

1.6K
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...
1.6K
Photoreceptors and Visual Pathways01:22

Photoreceptors and Visual Pathways

10.6K
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,...
10.6K

You might also read

Related Articles

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

Sort by
Same author

Factors affecting color vision: a systematic review.

International journal of ophthalmology·2026
Same author

Visual outcomes following implantation of intracorneal rings with sharp and round triangular cross-section designs in keratoconus.

International ophthalmology·2026
Same author

Comparative study of refractive errors between patients with Parkinson's disease versus age- and sex-matched healthy controls.

BMC neurology·2026
Same author

Comparison of binocular vision indices in Parkinson's disease patients <i>vs</i> age-sex-matched healthy controls.

International journal of ophthalmology·2026
Same author

Using low-dose atropine in control of intermittent exotropia.

Clinical & experimental optometry·2026
Same author

Agreement between Scheimpflug-based optical biometer with partial coherence interferometry in patients with keratoconus.

Scientific reports·2026

Related Experiment Video

Updated: Mar 15, 2026

Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients
07:06

Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients

Published on: March 29, 2022

3.4K

Does astigmatism alter with cycloplegia?

Amir Asharlous1, Hassan Hashemi2, Ebrahim Jafarzadehpur3

  • 1Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.

Journal of Current Ophthalmology
|September 1, 2016
PubMed
Summary

Cyclopentolate 1% eye drops significantly alter astigmatism measurements, particularly "with the rule" and "against the rule" types. Oblique astigmatisms were unaffected, and spherical equivalent values shifted towards hyperopia.

Keywords:
AgreementAstigmatismCycloplegiaNoncycloplegia

More Related Videos

Author Spotlight: Advancements in Refractive Surgical Correction for Presbyopia and Exploring Postoperative Visual Acuity
05:46

Author Spotlight: Advancements in Refractive Surgical Correction for Presbyopia and Exploring Postoperative Visual Acuity

Published on: September 20, 2024

860
Subjective Refraction Test Using a Smartphone for Vision Screening
05:36

Subjective Refraction Test Using a Smartphone for Vision Screening

Published on: October 18, 2024

1.9K

Related Experiment Videos

Last Updated: Mar 15, 2026

Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients
07:06

Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients

Published on: March 29, 2022

3.4K
Author Spotlight: Advancements in Refractive Surgical Correction for Presbyopia and Exploring Postoperative Visual Acuity
05:46

Author Spotlight: Advancements in Refractive Surgical Correction for Presbyopia and Exploring Postoperative Visual Acuity

Published on: September 20, 2024

860
Subjective Refraction Test Using a Smartphone for Vision Screening
05:36

Subjective Refraction Test Using a Smartphone for Vision Screening

Published on: October 18, 2024

1.9K

Area of Science:

  • Ophthalmology
  • Optometry
  • Vision Science

Background:

  • Accurate refractive error assessment is crucial for vision correction.
  • Cycloplegic agents are used to relax accommodation for precise refraction.
  • Understanding the impact of cycloplegia on astigmatism components is essential.

Purpose of the Study:

  • To evaluate the effect of cyclopentolate 1% on both spherical and cylindrical refractive components.
  • To analyze changes in astigmatism using power vector analysis (J0 and J45).

Main Methods:

  • Refraction measurements were taken before and 30 minutes after cyclopentolate 1% instillation.
  • Study included 375 eyes from 195 subjects (3-59 years).
  • Power vector analysis (J0, J45) was employed to compare cylindrical data.

Main Results:

  • A statistically significant difference was observed in J0 values (P=0.006), indicating changes in "with/against the rule" astigmatism.
  • J45 values showed no significant difference.
  • Cycloplegic refraction resulted in significantly more hyperopic spherical equivalent (SE) values (mean difference +1.16 ± 1.20 D).
  • SE differences were negatively correlated with age.

Conclusions:

  • Cyclopentolate 1% significantly shifts astigmatism components, affecting "with the rule" and "against the rule" astigmatisms.
  • Oblique astigmatisms remained unaffected by cyclopentolate.
  • Further research is needed to elucidate the mechanisms behind cycloplegia-induced cylinder changes.