Human sight uses about 500 megapixels. Now, imagine someone who uses more than 500 megapixels (with the same width), I assume that he would see things more accurately. So my question is : - how many pixels would he need to see cells or even atoms ? Bonus : - what determines the number of pixel of human sight ?
Let's start by assuming your previous statement (which would be interesting if true) is accurate, and that humans really do see at 500 megapixels.
As found here, the smallest object the naked eye can see is about 0.04mm.
We know that the average nuclear radius is in and around 1.2 femtometres- this is over one billion times smaller. In fact, to be exact, seeing a hydrogen atom with the naked eye would mean your vision is 33.3 billion times more powerful than that of a healthy individual.
Congratulations, you have a visual resolution of 16.8 exabytes.
To get my bonus point, I believe you're referencing this article, which says the lowest camera resolution people think is truly lifelike is 576 megapixels. Our brains are only capable of transferring this resolution of data along our optic nerves.
Cameras and the human optic nerve are incomparable in function: start reading into either how CMOS cameras work or photochemistry and you'll see why. Light on the whole is a tricky subject, but I guess if we wanted to measure the camera resolution of the human eye, you could take the smallest square we could theoretically see (0.04mm) and find out how many of those we could fit into our field of view. Interestingly, using some sphere math, we can only see 36.8 million of these tiny 0.04mm squares at any one time, which should illustrate my point that cameras and eyes work very differently. We work with shapes and patterns, not ones and zeroes.
Edit: Just to be clear- seeing atoms with the naked eye is not justifiable scientifically. Interesting concept, though- keep working on it.