We all know that a digital camera has a figure measured in pixels, usually in the scale of megapixels. This figure shows how many pixels or color dots can this camera capture in one image. A 1920 by 1080 resolution for example means that each image will be composed by 2.073.600 pixels or dots. We call this 2MP resolution.
So, can we estimate the resolution of the human eye? It turns out that its not that simple at all. As a matter of fact, the human eye does not work the same as the digital cameras. If a digital camera had a sensor as "good" as the human eye sensor, a snapshot would look something like this:
...which sucks big time. Moreover, the human eye has a blind spot inside which we are literally unable to see, and amazingly this blind spot is right in front of us!!! Let alone the fact that we always see the tip of our nose and the glasses (if any). The brain comes to the rescue, filtering, smoothing, jointing, removing and doing everything needed to get a better view of the cosmos out there.
But that does not happen with the digital sensors. There is no "brain" to work out a series of disrupted snapshot. The sensor must provide all the details of each image, so there is no direct comparison.
Instead, we can indirectly compare the resulting image of our eyes with a digital sensor. Check out the following video from Vsauce...