Sleep onset latency

MSLT Scores
MinutesSleepiness
0–5Severe
5–10Troublesome
10–15Manageable
15–20Excellent
A sleep onset latency of 0 to 5 minutes means severe sleep deprivation, 5 to 10 minutes is "troublesome", 10 to 15 minutes indicates a mild but "manageable" degree of sleep debt, and 15 to 20 minutes is indicative of "little or no" sleep debt.:341–342

In sleep science, sleep onset latency (SOL) is the length of time that it takes to accomplish the transition from full wakefulness to sleep, normally to the lightest of the non-REM sleep stages.