Effect of 19" vs 17" monitor on stimuli?

[jarvis24]

[edited from support email]

I have a rather random question for you about MediaLab and DirectRT. One of the monitors has been replaced in our computer lab and the replacement is 19" rather than 17". Tanya was wondering whether this might create a problem for parafovial priming studies. When a stimulus is programmed to be presented parafovially, is the distance from the center fixed or is it a ratio of screen width? I just want to make sure there won't be a difference between what participants will see based on the monitor being used.