Related Experiment Video
Updated: Jun 19, 2026
09:29
A Standardized Obstacle Course for Assessment of Visual Function in Ultra Low Vision and Artificial Vision
Published on: February 11, 2014
Basic quantitative assessment of visual performance in patients with very low vision
Michael Bach1, Michaela Wilke, Barbara Wilhelm
1Sektion Funktionelle Sehforschung, University Eye Hospital Freiburg, Freiburg, Germany. michael.bach@uni-freiburg.de
Investigative Ophthalmology & Visual Science
|October 24, 2009
Summary
A new test battery effectively assesses visual function in patients with no light perception (NLP) to hand movement (HM) vision. This tool aids in comparing visual prostheses efficacy for low-vision individuals.
Area of Science:
- Ophthalmology
- Neuroscience
- Biomedical Engineering
Background:
- Developing visual prostheses involves various approaches like subretinal, epiretinal, optic nerve, or visual cortex stimulation.
- Evaluating the efficacy of these visual prostheses, especially for individuals with no light perception (NLP), requires standardized assessment methods.
Purpose of the Study:
- To present a method for comparing the efficacy of different visual prostheses in improving visual function.
- To assess visual function starting from no light perception (NLP) up to higher acuity levels.
Main Methods:
- A computer-based test battery, Basic Assessment of Light and Motion (BaLM), was developed.
- The BaLM assesses four visual dimensions: light perception, temporal resolution, light localization, and motion detection using forced-choice paradigms.
Main Results:
- The BaLM was tested on 73 eyes of 51 low-vision patients.
- Light and temporal resolution modules differentiated between NLP and light perception (LP).
- Localization and motion modules distinguished LP from hand movement (HM) and reached ceiling performance at higher acuities.
Conclusions:
- BaLM results showed systematic differences across very-low-acuity categories (NLP, LP, HM).
- The test battery provides quantitative assessment for visual function in the low-vision range.
- The BaLM is valuable for evaluating visual prostheses with varying temporal characteristics.
