7. a small circular opening or window.
8. a thick disk or lenslike piece of glass inserted in a roof, ship’s deck, etc., to admit light.
9. Optics. a lens of short focal length.
10. a lantern equipped with a lens of this sort.

Source: Dictionary.com.

The square was lit with a mixture of flambeaux, oil-lamps, bullseyes, candles and braziers.

Source: Von Bek, ‘The City in the Autumn Stars’, Michael Moorcock.