1876 39 365 In the northern towns of England, as well as in Scotland, the number of one-light meters,..greatly exceed those used in London.
1908 A. L. Frothingham ii. 192 The lower story or two had a one-light opening.
1982 9 Apr. 198/3 The fixated light was vertically positioned in darkness to a height which the observer reported to be eye-level horizontal (‘one-light experiment’).