First thing to try is to increase the Size of the display to 125%. That might be all you need to do. Open Settings, Display to increase it. 
I recently purchased a DELL XPS and have been getting it ready for use.  I use my laptop roughly 5-6 hours a day for my work, so I need a machine that works well.  Since starting, i have had major headaches and eyestrain with the device.  I have fiddled with the CleanType system and brightness and I still have headaches, which is a major problem.   Is there anything that can be done about this? Thanks Chris
Eyestrain/Headaches