What does a visual acuity of 20/40 indicate about a client's vision?

A visual acuity of 20/40 signifies that the client can see at 20 feet what a person with normal vision can see at 40 feet. This means that the client's vision is not as sharp as that of a person with perfect vision (which is typically defined as 20/20). The first number (20) indicates the distance at which the test is performed, while the second number (40) represents the distance at which a person with normal vision can read the same letters. Therefore, a visual acuity of 20/40 demonstrates that the client experiences some degree of vision impairment but does not imply complete blindness or perfect vision.