Similar to the alignment of a car's wheels, eyelignment is a concept of spacial reasoning which enables a person to distinguish between straight and crooked. When a person erects a ladder or parks a car in a crooked manner even though it is perceived by that person as straight they are thought to have poor eyelignment.
*While cleaning the gutters out*
man 1: do you really think that ladder is standing up straight?
man 2: yea it's fine, why?
man 1: that's not even close, you should get your eyelignment checked.