There is nothing comparable to a shutter of the camera in the eye. The eyelid is like a lens hood. When the eyelid is open the image is continuously projected on to the retina unlike in a movie camera. However if the question is on frames per second (number of static images) required to produce a sense of seamless motion this article might be of some help. In video camera instead of a shutter speed it is the number of times the image on the sensor is sampled(recorded) per second electronically. The eye is more similar to a video camera. The retina has rods and cones which has variable 'refresher' rates which makes it more complicated to calculate exact figures.

Photography: What, How, Why Copyright © 2023 by Maria Politarhos and Randy Matusow is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

When you focus your lens on a subject (the lamp post in our example) the depth of field will change depending on the F stop you are using.

Just as in the previous example, the closer the subject is to the camera, the shallower the Depth of Field.  These three photographs are all focused on the same subject (planter-box in the middle of the hallway) and were taken with the same F stop and shutter speed, the only difference is the distance of the camera from the subject being photographed. The photographer kept walking closer to the subject (planter box).

Eye shutterfor sleeping

Depth of Field (DoF) refers to the distance between the closest and farthest objects that appears acceptably sharp in a photograph.

This is more like a volume knob than a shutter speed since the same signal comes out at the same rate of each light sensor, but it has a similar effect — it modulates the intensity of the image.

Eye shuttercamera

These three photographs above are all focused on the same subject (bird feeder) and were taken with the same F stop and shutter speed, the only difference is the distance of the camera from the subject being photographed. The photographer kept walking closer to the subject (bird feeder).

Actually I feel dumb but there is a simple answer to this question. You can get lost in the above physiology. The simpler answer is about 20 fps. Whenever strobing stops and persistence of vision takes over to create a continuous image is an interesting way to answer this question. That's how television and movies (and videos) work. 30 fps looks pretty smooth. It's not a perfect answer because 60 or 100 fps are functionally useful for situations like video games where fast reaction time is important.

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The larger the opening of the lens (small F Stop number) the less the Depth of Field. Only the person is sharp when using F 1.4 and the background appears blurred/out of focus.

The light receptor of the eye is a protein called Rhodopsin. To me the equivalent of shutter speed for the eye is the (de)sensitization of rhodopsin by phosphorylation. The brighter the light, the more sites on rhodopsin are phosphorylated, diminishing the intensity of the signal coming from the photo receptor via the transducin G protein that conveys the visual signal onward.

Notice how the size of the leaves in the planter gets much bigger while the size of the round windows on the door remains about the same. The depth seems to increase because the camera was brought closer to the subject.

Eye shutterapp

The human eye and its brain interface, the human visual system, can process 10 to 12 separate images per second, perceiving them individually.

Not all of your rods/cones fire at any given moment. Exception is when a bright flash of light is viewed. Recovery time from the resulting flash blindness is pretty slow -- seconds. But there's some photobleaching there, so maybe that's not fair.

The smallest opening (large F stop number) the greater the Depth of Field. The person and the background are sharp when using F 22.

Notice how the size of the leaves in the bird feeder gets much bigger while the size of the windows directly behind the feeder remains about the same. The depth seems to increase because the camera was brought closer to the subject.