The effect of glare on eye movements when reading

Glare is a very common source of image degradation when performing computer work. Since reading is a task that is very sensitive to image degradation induced disability glare affects reading performance.

To assess the effect of different glare conditions on eye movements when reading on a computer screen. Glare conditions have an impact on reading. This observation is based on the results from a study where we investigated how reading eye movements were affected by glare.

Sixteen subjects with normal vision participated in this study.

In a balanced repeated-measurement study, all subjects performed equal near-vision reading tasks. In addition to the condition of no glare three controlled conditions of glare were used: direct light, indirect light, and desk luminary. The subjects read three texts under each condition: First a short standardized text (IReST), secondly a longer newspaper text, and finally an additional IReST text. The texts were read on a Tobii T120 eye tracker.

The results show that glare does have a negative effect on reading performance. The more adverse the lighting condition was, the slower the reading speed became. The decrease was primarily a result of increased fixation durations. Both glare conditions of direct and indirect glare increased the fixation durations significantly (p < 0.05).

This study shows that even moderate glare conditions can have an impact on reading. The results show that it is important to follow recommendations of lighting design in computer work environment in order to avoid disability glare.