BLINDER

(of a person or animal) Unable to see, due to physiological or neurological factors.

(of an eye) Unable to be used to see, due to physiological or neurological factors.

Failing to see, acknowledge, perceive.

"Authors are blind to their own defects."

Something that blinds.

A bag or cloth put over the head of a difficult horse while it is being handled or mounted.

A screen attached to a horse's bridle preventing it from being able to see things to its side.

To fit (a horse) with blinders.

(by extension) To obstruct the vision of.