What is good design?

My first project at Kansas University! so excited! Well basically we had to pick an object which we find is "Good Design." After careful consideration I went straight to the thing I used most. My sunglasses. Here are some drawings to start off with my explanation on why I find sunglasses to be a good design.

and just because mac books are so fun!...

Sunglasses, their basic purpose is to protect our eyes from bright sunlight, and high energy visible light. They are a good design because they are something light and portable that sits perfectly on our noses and is held in place by our ears. The lens's are big enough to cover our eyes from light all around us. The shading on the lens also helps us to see clearly through them. There are many different designs of sunglasses. They come in many different shapes as a fashion trend, without taking away the purpose of the protective part of the design.