CASA is an automated system for sperm analysis which makes use of a software for the evaluation of sperm concentration, motility and morphology. The main advantage of CASA is that it eliminates the subjectivity associated with the human factor in manual semen analysis, thereby allowing for better standardization of the procedure. Furthermore, the software counts the spermatozoa more accurately, can calculate and record their exact speed and movement trajectory as well as the dimensions of their heads, midpieces and tails for more accurate morphology evaluation. Using computer aided sperm analysis also allows better visualization of the results, which aids patient understanding.