How many frames per second can the human eye see?
It’s Complicated
This question is not the same as asking how many frames-per-second are necessary to avoid seeing choppy images or flickering in video. There is an extreme difference between the point at which motion becomes fluid and the highest limits of fps perception.
Frame rate, or frame frequency, is the frequency (rate) at which an imaging device produces unique consecutive images called frames. The term applies equally well to computer graphics, video cameras, film cameras, and motion capture systems. Frame rate is most often expressed in frames per second (FPS), (fps) and in progressive scan monitors as hertz (Hz). [1]
The Amazing Human Eye
The human eye-brain-combination can see well over 200 frames per second, and as of today, there has not been a method to fully test the eye to its limits. The 60 or 100 frame per second limit commonly quoted in the past is completely false. Such low frame rates are easily distinguishable from higher frame rates and without the aid of special measuring instrumentation.
How The Eye Processes Light
Humans detect light when it is focused onto the retina of the eye by the lens. Light rays are perceived at the speed of light by our eyes as it enters. The retinas interpret light with two types of cells; rods and cones. The rods and cones are actually cells on the surface of the retina, and a lack thereof is one leading cause of blindness.
Measurements such as color, intensity, and position are all forms of information transmitted to the optic nerves by the retina. The optic nerve sends this data at the nerve impulse speed into the Visual Cortex part of the brain.
Rods are fairly simple cells that detect the intensity of light. Their response time is extremely quick. These cells control the amount of neurotransmitter released which is the direct result of light stimulation.
Cones on the other hand, are much more complex. These cells on the retina are the red, green, and blue color inputs (RGB) of our visual system. The three parts of these cones detect different wavelengths of light and that light’s intensity which results in varying amounts of neurotransmitters transmitted through the optic nerves on route to the brain. The response time of these cells is slower than the more streamlined rods.
Rhodopsin is a pigment of the retina that is responsible for both the formation of the photoreceptor cells and the first events in the perception of light. Rhodopsin of the rods most strongly absorbs green-blue light and therefore appears reddish-purple, which is why it is also called “visual purple”. It is responsible for monochromatic vision in the dark. [2]
There is no one correct answer
The reaction time of the rods and cones in your eyes depends on the frequency change from one color to the next and the brightness. Because of these variables there’s no one correct answer.
1. “Frame Rate.” Wikipedia. 2010. Wikimedia Foundation, Inc.. 2 Sept 2010
2. “Rhodopsin.” Wikipedia. 2010. Wikimedia Foundation, Inc.. 2 Sept 2010
