Setting up a monitor correctly can make a huge different in comfort levels when looking at a monitor, especially for an extended period of time.
There are a number of things that can be done to make your monitor more comfortable to view. Glare from windows is a common problem which can easily be overcome by positioning the monitor to a right angle of the window. If this is not possible, a set of blinds to keep the sun out, especially during the winter months when the sun can be very low during office hours will help reduce this problem.
Your monitor should be as close to directly in front of your face as possible when you are sat at your desk. There should be no need to twist your body or turn your head in order to see it, and at most it should be at a 35 degree angle from your sitting straight position. Adjusting the height of your screen so that the centre of the monitor is at eye level is ideal for most people, however computer users wearing bifocal glasses may find it more comfortable to have the monitor slightly lower than this. How high this is will vary depending on your own height and sitting position as well as how far away from you the monitor is. Ideally your monitor should be as far back as is possible without straining your eyes when you read what is on the screen. For most people this will mean it is somewhere between 50cm and 100cm away from your face.
Conference room screens
As meetings can sometimes involve spending an entire day looking at a screen from a distance it is just as important to get the screen set up properly in your conference room as it is at your desk. This might involve moving furniture around as well as the screen itself. Office screen wall mounts can be particularly useful here, having your screen positioned where you want is possible with these.
It is unusual for everybody to have a perfect view when many people are looking at the same screen, but it should be possible to make sure there are no lights or windows causing glare on the screen. Installing blinds will stop any outside light from coming in, whilst having multiple sets of lights in big rooms mean that those nearest the screen can be off without having to sit in the dark.
If the room is rectangular, consider having the screen on the long end. Whilst this may slightly reduce the number of people who can sit around the table, it will greatly improve both the viewing angle and distance.
Everyone will have their own personal preferences about what they find comfortable, however if you have never sat at a properly configured workstation you may not realise how uncomfortable the position of your monitor is until you try moving it. The above advice should help you identify the best way of setting up your monitor, and after spending a few days getting used to the new positioning you should find yourself experiencing a better posture and fewer aches and pains whilst sitting at your desk.