0 something that you are shown, such as a picture, film, or map, in order to help you understand or remember information --
1 a picture, film, map, etc. designed to help people understand or remember particular information: --
The sandwich concept is a revealing visual aid.
Without the visual aid, immediate knowledge of incidents in the bay will be delayed.
The visual aid, which, we are told, will take the place of the printed word in centuries to come, has not yet had that effect.
If this is sincerely meant, why not a visual aid, in view of the importance of the disease which we are discussing?
Lines for visual aid only.
However, it does not mention any visual aid in relation to their treatment.
The visual aid was presumably deemed necessary because the text does not make clear what inference we are to draw.
Note that lines are drawn as a visual aid only.!
