Reading Mobility Visual Assesment Evaluation of Devices
Letter charts are the standard tool for visual assessment because they are quick and relatively stable over a wide range of testing conditions. However letter charts do not test many essential aspects of visual function and are insensitive to many of the early signs of visual impairment.
We routinely use and are constantly developing new and more sensitive tests of visual function, including sensitivity to motion, colour, low as well as high contrast images and natural images. We examine how sensitivity is affected across the visual field and monitor eye movements, so that subjects cannot involuntarily adopt a different area of their eye that might not be affected. These tests are used provide early indications of specific sensory losses.
We attempt to relate these laboratory measurements to real-world tasks so that we can identify everyday tasks, such as reading or mobility, that might be particularly affected by the visual impairment. These results are used to inform the development of assistive devices that maximise residual visual function and to guide targeted rehabilitation training.