One of the points of conflict between naturalists and theists is the origin of the human eye. Naturalists insist that natural, random evolutionary processes have designed the eye whereas most theists believe that the eye has been designed by an intelligent agent.
There are a couple of arguments naturalists have employed to buttress their case, but the most well-known has for most of the twentieth century been the assertion that the eye is in fact poorly designed. If an intelligent agent designed it, the argument goes, he did a lousy job of it.
On the other hand, if blind evolutionary processes were the "agent" at work then we would expect sub-optimal designs to occur in living things, and this is what we find in the structure of the eye.
This nine-minute video explains in very clear terms why the argument based on the alleged poor design of the eye has fallen into disfavor among biologists and why discoveries in the twenty-first century have shown the eye to be even more marvelously designed than was previously thought.
The video is quite well done and very informative:
