The highest contrast ratio of the LS23C65 is 1000:1. That's 100% less contrast ratio than a 20000000:1 PC monitor, which is the most frequently found contrast ratio. Across all medium monitors that have been on the market for more than two years the contrast ratio ranges from Mega Contrast to 100000000:1.
It may also be worth considering one of the alternative PC displays that have a 1000:1 dynamic contrast ratio currently available including cheaper PC displays such as the LS23C350 (£147.15), or the NS240 both from Samsung or the LG 23M45.
If the contrast ratio of this LCD screen is too low for you then you might want to consider the iiyama X2485WS (£220.36) (3000:1), or the Benq BL2410 (£172.11) (3000:1) which is also higher rated.