Is the eye more sensitive to intermittent light/flashlight?

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In summary, the eye is more sensitive to intermittent light compared to continuous light due to its evolutionary adaptation to detect quick changes in light. When exposed to intermittent light, the eye responds with the pupillary light reflex, which helps protect the retina from damage. While exposure to intermittent light is generally not harmful, extremely bright or intense light can cause temporary or permanent damage. As we age, the eye's sensitivity to intermittent light decreases. However, intermittent light can also have positive effects on the eye, such as improving visual acuity and contrast sensitivity in individuals with certain eye conditions. Further research is needed to fully understand the effects of intermittent light on the eye.
  • #1
Tsunnnami
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Thread is locked -- schoolwork must be posted in the Homework Help forums with work shown
Is the eye more sensitive to intermittent light/flashlight than to constant light , if both have the same intensity ?
 
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  • #4
Tsunnnami said:
It doesn't say
The first paragraph speaks of the purpose of the iris. What happens if you shine a light into someone's eye?
 
  • #5
Tsunnnami said:
Is the eye more sensitive to intermittent light/flashlight than to constant light , if both have the same intensity ?

What exactly do you mean by "more sensitive"? Why do you think it should be more sensitive when the eye requires time to adjust its pupil during exposure of light? And how "intermittent" is this? If the time in between light flash is less than 0.02 seconds, you can no longer tell the difference between intermittent source and cw source (why do you think old-fashion film movies run at 24 frames per second?). I wouldn't call this "more sensitive" at all.

Zz.
 
  • #6
ZapperZ said:
What exactly do you mean by "more sensitive"? Why do you think it should be more sensitive when the eye requires time to adjust its pupil during exposure of light? And how "intermittent" is this? If the time in between light flash is less than 0.02 seconds, you can no longer tell the difference between intermittent source and cw source (why do you think old-fashion film movies run at 24 frames per second?). I wouldn't call this "more sensitive" at all.

Zz.
Logically if you flash a light into someone's eye, he blinks. Doesn't this mean that the eye is more sensitive to flash-light ?
 
  • #7
Tsunnnami said:
Logically if you flash a light into someone's eye, he blinks. Doesn't this mean that the eye is more sensitive to flash-light ?

No, it means that the brain and reflex action are "sensitive" to the sudden appearance of bright light. This is a physiological question, not a physics question.

This is why are asked you to DEFINE what you mean by "sensitive". As someone who works in increasing sensitivity and resolution of light detectors, I define "sensitivity" as the quantum efficiency of that detector.

You are now in a science forum. You need to be aware that many of the terms being used often have clear, well-defined meanings in science/physics. So when you use something, unless you clearly state exactly what you are seeking, then either we interpret this the way it is used in science, or it will make for a very confusing discussion, like this one.

Zz.
 
  • #8
Tsunnnami said:
Logically if you flash a light into someone's eye, he blinks. Doesn't this mean that the eye is more sensitive to flash-light ?
The effect I was fishing for was the fact that if you shine a light into a person's eyes, the pupils contract. But please do not let that distract you from answering @ZapperZ
 
  • #9
This was all that was specified in the exam question. We got no further details or specifications.
 
  • #10
Tsunnnami said:
This was all that was specified in the exam question. We got no further details or specifications.

This this is school-type question that should be done in the HW/Coursework forum, AND must be accompanied by (i) the full question and (ii) a show of what you attempted.

If this is an exam question that you should be doing on your own, but instead you sought help on here, then you are in deep doo doo.

Zz.
 
  • #11
Tsunnnami said:
This was all that was specified in the exam question. We got no further details or specifications.
Thread is locked.

@Tsunnnami -- As ZapperZ says, schoolwork questions go in the Homework Help forums, and you fill out the Template there to show your work. Please do not post schoolwork questions in the technical forums again here at the PF.
 

1. Is the eye more sensitive to intermittent light or continuous light?

The eye is more sensitive to intermittent light compared to continuous light. This is because the eye has evolved to detect quick changes in light, which are typically associated with movement or danger. Continuous light does not provide this quick change, so the eye does not respond as strongly.

2. How does the eye respond to intermittent light?

When the eye is exposed to intermittent light, the pupil will constrict and dilate rapidly in response to the changes in light intensity. This is known as the pupillary light reflex. It is a protective mechanism that helps the eye adjust to different lighting conditions and protect the retina from damage.

3. Can exposure to intermittent light damage the eye?

In general, exposure to intermittent light will not damage the eye. However, if the light is extremely bright or intense, it can potentially cause temporary or permanent damage to the retina. This is why it is important to not stare directly at bright flashes of light, such as from a camera flash or a welding torch.

4. How does age affect the eye's sensitivity to intermittent light?

As we age, the eye's sensitivity to intermittent light decreases. This is due to a natural decline in the function of the retina and the pupil. Older adults may find it more difficult to adjust to changes in lighting conditions and may experience more discomfort or glare when exposed to intermittent light.

5. Can intermittent light have any positive effects on the eye?

Yes, intermittent light can have positive effects on the eye. For example, studies have shown that exposure to flickering light can improve visual acuity and contrast sensitivity in individuals with certain eye conditions, such as amblyopia (lazy eye). However, more research is needed to fully understand the potential benefits and risks of intermittent light on the eye.

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