The objective of the present study is to expand our understanding of visual complaints in people with multiple sclerosis (MS) with the aim of exploring potential rehabilitation approaches for treating visual complaints. Visual complaints are increasingly recognized as a core manifestation of MS. Up to 90% of people with MS report all kinds of visual complaints, such as blurry vision, double vision, being blinded by bright light, a reduced visual field and having trouble with depth perception. Since intact vision is quintessential to many activities of daily life, such as reading or car driving, these complaints affect independent participation to a great extent. The complaints cannot be fully explained by optical neuritis (a common symptom of MS) or other treatable visual or ophthalmological disorders. Moreover, there are no rehabilitation programs available for visual complaints in people with MS. However, the complaints are not yet understood well enough to develop effective rehabilitation strategies to reduce the impact of the visual complaints.

Visual complaints were assessed using the Screening Visual Complaints questionnaire. 68 people with MS with visual complaints, and 37 with hardly any visual complaints received a standard visual function assessment and a neuropsychological assessment. Correlations between the visual complaints, visual functions and cognitive functions were calculated. In addition, correlations were calculated between several visual functions and a composite score of the neuropsychological assessment.

Only some specific visual measures related to visual complaints, with small to moderate effect sizes. While most specific cognitive functions did not show correlations, measures indicative of overall cognitive capacity in people with MS (such as motor speed) consistently correlated with different kinds of visual complaints. Additionally, visual functions that related to visual complaints also correlated with the composite score for cognitive functioning.

Our study serendipitously showed that in developing or composing effective rehabilitation strategies for visual complaints, we should look beyond a person’s visual functioning: first, the overall cognitive capacity should be taken into account. Second, visual functioning and cognitive functioning are closely related. These results indicate that visual complaints may be a result of a general decline of the visual and/or cognitive system as one. When treating these complaints, low vision rehabilitation and neuropsychological rehabilitation strategies may be combined. Strategies should not focus on specific visual or cognitive functions, but at making the visual world more easily accessible, or more easily visible, to reduce the impact on the visual system and cognitive capacity. Strategies could range from applying more contrast in the environment to psycho-education. Future research should focus on developing rehabilitation programs and assessing their effectiveness in people with MS or with other types of non-acquired brain injuries.