As far as I understand it, the only thing that allows man to observe the world around him is by way of this little invention called "the lens".
If it wasn't for this lens to focus photons coming from the same point on the retina than the eye would just get bombarded by a huge load of photons with no idea of where these came from and no means of building up a coherent picture. Am I the only one that finds this mind boggling that nature come up with this neat device that allows us to make sense of the world?
And if you follow through on this then we are damned lucky that light changes direction when passing from one medium to another. How would you else go about making a lens?
If my reasoning is flawed or you share my amazement, please respond.
