Incidence of self-reported sleep disturbances and mean Pittsburgh Sleep Quality Index (PSQI) in the six different sub-groups of the blind and visually impaired respondents.

RLP (reduced conscious light perception) is shown in the first three columns; LP (conscious light perception in both eyes), is shown in the second three columns. Data are shown as raw numbers and percentages (where appropriate). Where means are given, the standard error is shown in parentheses.