The highest contrast ratio of the Acer DA220 is 100000000:1. That's over five times the contrast ratio of a 20000000:1 LCD screen, which is the most common contrast ratio.
A 100000000:1 dynamic contrast ratio is in fact the best contrast ratio amongst all PC screens of this age and type.
The worst contrast ratio amongst comparable types of PC monitor is Mega Contrast.
It may also be worth also looking at one of the other PC screens that have a 100000000:1 dynamic contrast ratio currently available including the Acer K272HU ($227.99) which has a better Rating; or the Acer V276 which is cheaper.