The highest contrast ratio of the Viewsonic VA2246 is 1000:1. That's 100% less contrast ratio than a 20000000:1 PC screen, which is the most common contrast ratio. Across all medium monitors that were launched more than two years ago the contrast ratio ranges from Mega Contrast to 100000000:1.
Alternative flatpanel monitors that have a 1000:1 dynamic contrast ratio currently available which you might want to consider include the Asus VS228D (£106.89) which is cheaper.
If the contrast ratio of this LCD screen is too low for you then you might want to consider the HP ZR22w (£140.26) (3000:1 and cheaper), or the Edge10 ET220a (10000:1 and cheaper).