Resolution of human eye

Optical Resolution
An imaging system maybe an individual component including the lens, recording and display components. Each of these components results in the optical resolution of a system, as well as the environment.

Resolution of Human Eye
The resolution of an image is the smallest detail of the image.The resolution is determined using :-
 * Wavelength method: resolution = wavelength of the signal used
 * Pulse length method: resolution = half pulse length = pulse duration x speed of pulse/2

When the aim of a system is to present data for the humans for processing, the human eye is often a limiting factor. The best acutness of vision of the human eye is at its optical center which is called the fovea, which is less than 1 arc-minute/line pair, reducing rapidly away from the fovea. The human brain requires more than just a line pair to understand what the eye is imaging. Visual acuity is defined as 1/a, where a is response in x/arc-minute, where x is the line pair. So when we define x to be a line pair, the 1/a value is 1.7 under good lighting conditions.The acuity of 1.7 when light level is greater than 0.1 Lambert. A Lambert is a unit of luminance to 1/pi candela per square centimeter. The eye moves rapidly in a small angular amounts and continually update the image in one's brain to paint the detail. We also have a pair of eyes and our brain, and both combine the signals to increase the resolution,also our eye move very rapidly to gather more information from the scene. Because of these factors, a higher resolution image is possible with the number of photo receptors in the retina. If we consider a view in front of you that is 90 degrees by 90 degrees,by calculation of pixels the result will come to be 324 megapixels. The eye does not recieve that amount of pixels at once but due to the movement of the eye ball to gather more information and details from the scene to get this amount of pixels.