Is the eye more sensitive to intermittent light/flashlight?

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Discussion Overview

The discussion centers around the sensitivity of the human eye to intermittent light compared to constant light, specifically when both sources have the same intensity. The inquiry touches on physiological responses, definitions of sensitivity, and the implications of pupil adjustment in response to light exposure.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Homework-related

Main Points Raised

  • Some participants question what is meant by "more sensitive," suggesting that the eye's response may depend on the duration and frequency of the intermittent light.
  • One participant notes that if the interval between flashes is less than 0.02 seconds, the distinction between intermittent and constant light may not be perceivable.
  • Another participant argues that blinking in response to a flash of light indicates sensitivity, but clarifies that this response is more about brain reflexes than the eye's sensitivity to light itself.
  • There is a call for clearer definitions of terms like "sensitivity," as they can have specific meanings in scientific contexts.
  • A participant mentions that the original question lacks sufficient detail, which complicates the discussion.
  • Some participants express that the question may be more appropriate for a homework forum, indicating it may not be suitable for technical discussion without further context.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the definition of sensitivity or the implications of the eye's response to light. Multiple competing views remain regarding the interpretation of sensitivity and the physiological responses involved.

Contextual Notes

The discussion is limited by the lack of specific details in the original question, which affects the clarity of the responses. There is also an emphasis on the need for precise definitions in scientific discussions.

Who May Find This Useful

This discussion may be of interest to those studying physiology, optics, or related fields, as well as students seeking clarification on concepts related to light sensitivity and reflex actions.

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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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?
 
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.
 
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 ?
 
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.
 
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
 
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.
 

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