1998 Toyota 4Runner Owners Manual - Page 105

4RUNNER (1998) Sun visors- -Vanity mirrors To reduce glare from the headlights of the vehicle behind you during night driving, operate the lever on the lower edge of the mirror. Daylight driving-Lever at position 1 The reflection in the mirror has greater clarity at this position. Night driving-Lever at position 2 Remember that by reducing glare you also lose some rear view clarity.