How many dimensions are in the display of an A-scan?

The display of an A-scan is indeed a one-dimensional acoustic display. In A-scan ultrasonography, the data is represented as a single line graph where the horizontal axis indicates time or distance, allowing the identification of the reflected echoes from different internal structures. This method primarily provides information about the depth and location of these structures by showing a single dimension of data—essentially, amplitude versus time or depth.

The one-dimensional nature of the A-scan display contrasts with B-scan, which provides a two-dimensional view, showing cross-sectional images of the eye, and C- or D-scans that can reflect additional dimensions in imaging. A-scan is primarily used for measuring distances, such as in biometry for calculating intraocular lens power, making its one-dimensional layout well-suited for this purpose.