The highest contrast ratio of the I2260PWHU is 50000000:1. That's over ten times the contrast ratio of the most frequently found dynamic contrast ratio of 5000000:1. Across all medium monitors that have been on the market for a similar time to the I2260PWHU the contrast ratio ranges from Mega Contrast to 100000000:1.
There are a number of alternative LCD screens that have a 50000000:1 dynamic contrast ratio currently available which you might also want to consider including the VX2363SMHL (£97.00), or the VX2263SMHL (£104.38) both from Viewsonic which has a better Rating.
If the contrast ratio of this PC screen is too low for you then you might also want to consider the Asus VX239H (£114.97) (80000000:1) which also has a higher Rating.