Related Experiment Video
Updated: Feb 9, 2026
08:27
Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes
Published on: March 3, 2023
1.5K
Accommodation, Convergence, and Stereopsis in Dyslexic Schoolchildren
Monireh Feizabadi1, Ebrahim Jafarzadehpur2, Majid Akrami3
1Department of Optometry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Middle East African Journal of Ophthalmology
|June 15, 2018
Summary
Dyslexic children show reduced near point of accommodation (NPA) in both eyes and binocularly compared to their peers. Optometrists should assess NPA in children with dyslexia.
Area of Science:
- Ophthalmology
- Developmental Psychology
- Pediatrics
Background:
- Limited research exists on visual skills in dyslexic students, especially in Iran.
- Previous studies suggest a link between reading difficulties and binocular vision issues.
Purpose of the Study:
- To investigate and compare binocular visual functions in dyslexic children versus a control group.
- To assess near point of accommodation (NPA), near point of convergence (NPC), and stereoacuity.
Main Methods:
- A case-control study involving 27 dyslexic children and 40 controls (ages 7-13).
- Measurements included subjective push-up for NPA, standard push-up for NPC, and Titmus stereotypes for stereoacuity.
- Study conducted in Tehran, Iran.
Main Results:
- Dyslexic children exhibited significantly reduced monocular NPA (right eye P=0.003, left eye P=0.003) and binocular NPA (P=0.049).
- No significant differences were found in near point of convergence (NPC) (P=0.33) or stereoacuity (P=0.785) between groups.
Conclusions:
- Reduced monocular and binocular near point of accommodation is evident in dyslexic children.
- NPA assessment is recommended for children diagnosed with dyslexia by optometric clinicians.
Related Concept Videos
01:54Convergent Evolution
33.0K
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
33.0K
01:17Region of Convergence
957
The z-transform is a powerful mathematical tool used in the analysis of discrete-time signals and systems. It is a crucial tool in the analysis of discrete-time systems, but its convergence is limited to specific values of the complex variable z. This range of values, known as the Region of Convergence (ROC), is fundamental in determining the behavior and stability of a system or signal. The ROC defines the region in the complex plane where the z-transform converges, which can take various...
957
01:21Convergence of Fourier Series
427
The Fourier series is a powerful mathematical tool for representing periodic signals as an infinite sum of complex exponentials. In practice, this infinite series is truncated to a finite number of terms, yielding a partial sum. This truncation makes the approximation of the signal feasible but introduces certain challenges, particularly near discontinuities, known as the Gibbs phenomenon.
The Gibbs phenomenon refers to the persistent oscillations and overshoots that occur near discontinuities...
The Gibbs phenomenon refers to the persistent oscillations and overshoots that occur near discontinuities...
427
01:20Region of Convergence of Laplace Tarnsform
1.3K
The Region of Convergence (ROC) is a fundamental concept in signal processing and system analysis, particularly associated with the Laplace transform. The ROC represents an area in the complex plane where the Laplace transform of a given signal converges, determining the transform's applicability and utility.
Consider a decaying exponential signal that begins at a specific time. When deriving its Laplace transform, the time-domain variable is replaced with a complex variable. This...
Consider a decaying exponential signal that begins at a specific time. When deriving its Laplace transform, the time-domain variable is replaced with a complex variable. This...
1.3K
02:03Anatomy of the Circulatory System
98.2K
The human circulatory system consists of blood, blood vessels that carry blood away from the heart, around the body, and back to the heart, and the heart itself, which acts as a central pump. The systemic circuit supplies blood to the whole body, the coronary circuit supplies blood to the heart, and the pulmonary circuit supplies blood flow between the heart and lungs.
98.2K
02:55Exceptions to the Octet Rule
37.8K
Many covalent molecules have central atoms that do not have eight electrons in their Lewis structures. These molecules fall into three categories:
37.8K