What term is used to describe someone who cannot see?

The term used to describe someone who cannot see is "blind." This term specifically refers to the condition of lacking visual perception, which can be a result of various factors such as eye disease, injury, or congenital conditions. "Blind" encompasses a range of visual impairments, from partial to complete loss of sight.

In contrast, the other options describe different conditions: "deaf" pertains to a lack of hearing, "impaired" is a general term that could refer to various deficiencies in senses or functions, and "sighted" indicates the ability to see. Understanding these distinctions is important when discussing disabilities and the experiences of those who are visually impaired.