Most private health insurance programs cover occupational therapy services for disabilities, including low vision. occupational therapy services on a state-by-state basis. by occupational therapists to all beneficiaries in 2002. Referral by an optometrist or physician is required for Medicare coverage.
Biphasic sleep (or diphasic, bimodal or bifurcated sleep) is the practice of sleeping during two periods over 24 hours, while polyphasic sleep refers to sleeping multiple times â usually more than two.[1] Each of these is in contrast to monophasic sleep, which is one period of sleep over 24 hours. Segmented sleep and divided sleep may refer to polyphasic or biphasic sleep, but may also refer to interrupted sleep, where the sleep has one or several shorter periods of wakefulness.
Usually sleepers pass through five stages: 1, 2, 3, 4 and REM (rapid eye movement) sleep. These stages progress cyclically from 1 through REM then begin again with stage 1. A complete sleep cycle takes an average of 90 to 110 minutes, with each stage lasting between 5 to 15 minutes. The first sleep cycles each night have relatively short REM sleeps and long periods of deep sleep but later in the night, REM periods lengthen and deep sleep time decreases.