Figure 2. Prevalence of sleep disturbances, and rate of participants with lower physical and mental QOL among the three groups.

PCS, physical component score; MCS, mental component score. Lower PCS and MCS were defined respectively as ≤ 49.8 and ≤ 50.5 based on average values of the Japanese normative data. **p < 0.001 and *p < 0.05 in comparison between the visually impaired individuals and the control subjects. ‡p < 0.05 in comparison among the visually impaired individuals without light perception, those with light perception, and the control subjects (residual error ≥ 1.96).