Hello guys! I currently have a 23.5 inch samsung monitor. My pc is getting slow, and I want to go full mac (I already have macbook pro retina 13inch). I'm either going to get the 21.5 inch non-retina or the 27 inch non-retina. I'm afraid that the 27 inch might be too big, I don't want to strain my eyes.. I sit around 2.2 feet (27 inch/68cm) from my monitor right now. I think the imac will be a little further away, making it around 2.4 feet (add 2/3 inches and 5/6 cm). Please, give me advice, what would be wiser? I mainly do graphic designing. Don't tell me to get the retina one please. Also, please don't tell me that 27 inch might be "better" for graphic design. I think all sizes above 17 inch are enough for that. Thanks!