A children's game in which players take turns to place S's and O's on a grid, collecting points by creating an "SOS" sequence.
The conventional Morse code call made by a ship in distress.
Anything that blinks, such as the turn signal of an automobile.
Eye shields attached to a hood for horses, to prevent them from seeing backwards and partially sideways.
A black eye.
In Conway's Game of Life, an arrangement of three cells in a row that switches between horizontal and vertical orientations in each generation.
The eyelid.
Whatever obstructs sight or discernment.
To put blinkers on.