<span>The circadian rhythm fatigue is an everyday process of normal body downtime. It occurs due to any number of reasons, such as lack of sleep, exhaustion due to work or other activities, hunger, or even boredom. The best way to counter it is to get some rest or sleep.</span>
If this counts my parents used to tell me, Sitting too close to the tv would burn your eyes out.
Quite bloody for a young one.
Anyways, I know staring too long can hurt your eyes but not being too close or else i would have a lot of eye problems.
Answer: Perspective is very important in design so you can portray the depth and size you wish to design, it can also help prevent confusion of how something looks.
Hope this helps!! :)