Related Experiment Video
Updated: Jul 14, 2026
12:23
Dynamic Visual Tests to Identify and Quantify Visual Damage and Repair Following Demyelination in Optic Neuritis Patients
Published on: April 14, 2014
Reaction test for competence in visual pathway lesions
Fritz Dannheim1, Darmar Verlohr
1Augenarztpraxis und Orthoptik, Friedhofstr. 1, Seevetal, Germany. dannheim@uke.uni-hamburg.de
Strabismus
|May 25, 2007
Summary
This study evaluated visual performance in patients with visual pathway lesions and homonymous field defects using a simple reaction time test. The test effectively quantizes visual field loss and monitors rehabilitation progress.
Area of Science:
- Neuroscience
- Ophthalmology
- Visual Science
Background:
- Homonymous visual field defects resulting from lesions of the visual pathways significantly impair visual performance.
- Quantifying the extent of visual field loss and monitoring recovery are crucial for patient management and rehabilitation.
Purpose of the Study:
- To evaluate the performance in a visual environment for patients with visual pathway lesions and homonymous visual field defects.
- To assess the utility of a simple reaction time test in quantifying visual field defects and monitoring rehabilitation.
Main Methods:
- A central fixation or search target was presented in 11 positions within 34 degrees on a CRT, superimposed on a landscape.
- Reaction times were recorded in 24 patients with visual pathway lesions and homonymous visual field defects, and 18 normal subjects.
- The test duration was noted for both patient and control groups.
Main Results:
- The simple reaction time test effectively differentiated between patients with homonymous visual field defects and normal subjects.
- Test duration was significantly longer in neurological patients (four or more minutes) compared to normal subjects (about 1 minute).
- The test demonstrated sensitivity to visual field loss and potential for monitoring training effects.
Conclusions:
- This reaction time test is a simple, quick, and effective tool for evaluating visual performance in individuals with homonymous visual field defects.
- The test can quantify saccadic adaptation to disability and monitor the effectiveness of visual rehabilitation programs.
- Findings support the use of this test in clinical settings for managing patients with visual pathway lesions.
Related Concept Videos
01:24Color Vision
Color perception begins in the retina, the light-sensitive layer at the back of the eye. Two main theories explain how colors are seen: the trichromatic theory and the opponent-process theory. The trichromatic theory, proposed by Thomas Young in 1802 and extended by Hermann von Helmholtz in 1852, suggests that color vision is based on three types of cone receptors in the retina. These cones are sensitive to different but overlapping ranges of wavelengths corresponding to red, blue, and green.
01:12Visual Agnosia
Visual agnosia is a condition characterized by the inability to recognize visually presented objects despite having normal vision. For instance, a person with visual agnosia can describe the shape and color of an object but cannot identify or name it. This impairment does not affect their visual field, acuity, color vision, brightness discrimination, language, or memory. An example of this condition in a social setting is someone at a dinner party asking for "that silver thing with a round end"...