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...

$Influence of Earth's Curvature and Atmospheric Refraction on Leveling$ 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...

Crystal Density

Crystal Density

The crystal lattice structure of a material allows us to determine how many molecules exist in its unit cell. With this information, alongside the unit-cell parameters - three distance parameters (a, b, c) and three angular parameters (α, β, γ).Density (ρ) = (Z × M) / (a × b × c × NA)where:Z is the number of formula units per unit cellM is the molar mass of the substancea, b, and c are the edge lengths of the unit cellNA is Avogadro’s numberFor a simple cubic lattice, atoms are located only at...

You might also read

Related Articles

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

Sort by

Same author

Navigating Portal Hypertension and Splenomegaly: A Clinical Encounter With an Unusual Variant of Cruveilhier-Baumgarten Syndrome.

Cureus·2024

Same author

Exploration of Abiraterone acetate loaded Nanostructured lipid carriers for bioavailability improvement and circumvention of fast-fed variability.

Drug delivery and translational research·2024

Same author

Valorization of fish processing by-products for protein hydrolysate recovery: Opportunities, challenges and regulatory issues.

Food chemistry·2024

Same author

Heterogeneity in Antidepressant Treatment and Major Depressive Disorder Outcomes Among Clinicians.

JAMA psychiatry·2024

Same author

Harnessing pyroptosis for lung cancer therapy: The impact of NLRP3 inflammasome activation.

Pathology, research and practice·2024

Same author

Aetiology and epidemiology of surgical vitreoretinal presentations in an Australian paediatric population: A seven-year retrospective study.

Clinical & experimental ophthalmology·2024

Search research articles

Related Experiment Video

Updated: Jun 13, 2026

Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients

Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients

Published on: March 29, 2022

Population density and refractive error among Chinese children.

Mingzhi Zhang¹, Liping Li, Lizhen Chen

¹Joint Shantou International Eye Center, Shantou, Peoples Republic of China.

Investigative Ophthalmology & Visual Science

|May 7, 2010

Summary

Higher population density, not just near work, is linked to increased myopia risk in Chinese children. This finding suggests urban environmental factors beyond academics may drive myopia progression.

More Related Videos

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

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

Published on: September 16, 2025

$Subjective Refraction Test Using a Smartphone for Vision Screening$

Subjective Refraction Test Using a Smartphone for Vision Screening

Published on: October 18, 2024

Related Experiment Videos

Last Updated: Jun 13, 2026

Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients

Binocular Dynamic Visual Acuity in Eyeglass-Corrected Myopic Patients

Published on: March 29, 2022

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

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

Published on: September 16, 2025

$Subjective Refraction Test Using a Smartphone for Vision Screening$

Subjective Refraction Test Using a Smartphone for Vision Screening

Published on: October 18, 2024

Area of Science:

Ophthalmology
Public Health
Environmental Health

Background:

China faces rapid urbanization and a high prevalence of myopia.
Understanding the drivers of myopia in urban versus rural populations is crucial for public health interventions.

Purpose of the Study:

To investigate the factors contributing to the disparity in myopia prevalence between urban and rural Chinese children.
To identify specific environmental and behavioral correlates of myopia in a rapidly urbanizing Chinese population.

Main Methods:

Cycloplegic refraction was performed on 4612 children in a mixed rural-urban township in Guangdong.
Data collected included age, gender, parental education, near work, time outdoors, and neighborhood population density.
Multivariate analysis was used to assess associations with myopic refractive error.

Main Results:

Older age, increased near work, and higher population density were significantly associated with myopia.
Factors such as parental education, time outdoors, and neighborhood development index were not significantly linked to myopia.
Population density emerged as a key environmental correlate, independent of other studied factors.

Conclusions:

Higher population density is a significant factor associated with increased myopia risk in Chinese children.
This association appears independent of traditional risk factors like academic workload and time spent outdoors.
Further research is needed to elucidate the mechanisms linking population density to myopia development.