Current measures for assessing vision, such as charts and visual field testing, do not correlate well with how patients experience daily life tasks such as driving. However, the regulations on fitness to drive in glaucoma patients are still relying on those types of measurements.

The main objective of this work was to assess new ways of measuring vision related to real world tasks, with a focus on driving in glaucoma patients. First, a literature review showed that the relationship between driving and visual and cognitive impairment is mediated by several factors, including degree of impairment, compensation, and research design. Then, the effect of visual field defects on neuropsychological testing was studied in a glaucoma group and a healthy participant group. We found that caution is advised when making conclusions about cognition when glaucomatous visual field defects could influence performance, for example in the Trail Making Test A. This study continued with driving in a driving simulator, in which glaucoma patients did not perform worse than the healthy group. Finally, four new functional vision tests were evaluated, including a test for basic reaction time, face discrimination, visual search and a visual field test using a built-in webcam that monitors compliance. All of these four new ways of testing functional vision were found to be reliable and stable measures of functional vision.

These studies show that the relationship between visual impairment and real-world functioning is complex and mediated by many different factors. Therefore, more tests are needed to evaluate real-world functioning of glaucoma patients instead of isolated visual acuity and visual field tests. Tests outside of an ophthalmological setting on portable devices that take into account vision and cognition could be used to help explain the relationship between visual impairment and real-world performance.