[watmough]

You might want to get your vision checked, adjust your screen resolution, color balance your monitor, and try and find a healthy relaxed posture.

Mine is feet resting on my lower desk frame taking the weight of the back of my thighs, with my back supported by the chair, i.e. not unsupported.

This is a big change in posture from how I used to be, and much less stressful.

I'm getting into my mid-40's and I'm still pulling 4 hour programming sessions at night with not much but some stiff legs and tiredness to show.

Also, if you have dry itchy skin, get a RadioShack temperature and humidity device and if the air's too dry, try a humidifier.