Colour vision deficiency and Visual defect

Colour vision deficiency noun - Genetic inability to distinguish differences in hue.

Visual defect and colour vision deficiency are semantically related. In some cases you can use "Visual defect" instead a noun phrase "Colour vision deficiency".

Visual defect noun - Impairment of the sense of sight.

Colour vision deficiency and visual defect are semantically related. Sometimes you can replace phrase "Colour vision deficiency" with "Visual defect", this phrases are similar.