A visually impaired patient whose vision cannot be corrected by any conventional means is known as what?

A visually impaired patient whose vision cannot be corrected by any conventional means is classified as a person with low vision. Low vision refers to a significant visual impairment affecting daily life, where standard corrective measures like glasses or contacts do not provide sufficient vision improvement. This classification helps in understanding the level of assistance and specialized services they might require to enhance their quality of life.

The other terms provided in the choices refer to different conditions. A monocular patient specifically has vision in only one eye, which does not necessarily equate to a broader category of low vision. Heterochromia refers to a difference in coloration, usually of the eyes, and does not relate to vision impairment. A cataract patient has clouding of the eye's lens, which can often be treated surgically to restore vision, thus not aligning with the description of someone whose vision cannot be corrected by conventional means. Therefore, the definition of low vision directly aligns with the characteristics mentioned in the question.