Humans treat themselves as the measure of all things, and using visual methods to distinguish, by seeing differences and similarity. (frieze.com)
However, visual methods allow the damage to be detected in a rather advanced state only. (sciencedaily.com)
For example, the idea that some may learn more effectively through visual methods of teaching, like videos or demonstrations, whereas others absorb information best when it is conveyed through auditory lessons (think lecture style). (qaeducation.co.uk)