Double vision and Visual impairment

Double vision noun - Visual impairment in which an object is seen as two objects.

Visual impairment and double vision are semantically related. In some cases you can use "Visual impairment" instead a noun phrase "Double vision".

Visual impairment noun - Impairment of the sense of sight.

Double vision and visual impairment are semantically related. Sometimes you can replace phrase "Double vision" with "Visual impairment", this phrases are similar.