Colour vision deficiency and Vision defect

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

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

Vision defect noun - Impairment of the sense of sight.

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