The highest contrast ratio of the MultiSync EA273 is 25000:1. That's 100% less contrast ratio than a 20000000:1 PC screen, which is the most common contrast ratio. Across all medium monitors that have been on the market for more than two years the best contrast ratio is 100000000:1 and the worst is Mega Contrast.
It may also be worth considering one of the alternative LCD screens that have a 25000:1 dynamic contrast ratio currently available including the NEC MultiSync EA244WMI ($249.99) which has a better Rating.
If you want a PC screen with a higher contrast ratio then you might also want to consider the Lenovo LT2452p (1000000:1 and cheaper); or the U2713H ($675.80) (2000000:1 and higher rated), or the U2913WM ($308.27) (2000000:1 and higher rated) both from DELL.