Yeah, it is difficult to judge what is too bright or adequate for another person because people have different sensitivity level. I will assume the doctors that
hang-the-9 have average brightness sensitivity for humans. If you think your own brightness sensitivity is average, then the Dell will probably not bother you.
If illumination is a real concern then you should consider the Dell 2412M which can go down to 46 cd/m². If you are working with a tight budget then you need to consider the following:
1. Simply buy the Dell 2312HM and be done with it. If the illumination to too high then either just deal with it, or ship it back for a refund less a 15% restocking fee and the cost to ship it back.
2. Step up to the Dell 2412M, you will be paying more, but you have the satisfaction of knowing that you will not be straining your eyes and / or you will not be getting headaches.
hang-the-9 :
I work in radiology reading rooms that are dark all the time, and we use the same class of monitors as the DELL, none of the doctors have complained at default brightness. We use LG and Planar monitors though not Dells.
I hope you are referring to Planar's consumer level monitors and not the medical class high precision monitors, otherwise you more or less devastated Planar's reputation of producing high quality monitors for the medical field for X-rays, CAT scan and MRIs amongst others.
The Planar PX2611w was probably their last truly great consumer level monitor. I'm glad I own one. I love H-IPS monitors.