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.
A blinking light on a motor vehicle that indicates the direction in which it is about to turn.
A semaphore device with a steady light that served the same purpose on early vehicles.