Are there dealers who offer measuring of eye pupil size? (13 Viewers)

[Swedpat]

This would be a valuable service. Probably the majority of binocular buyers(and some dealers as well) are ignorant about the the importance of the eye pupil size in relation to exit pupil.
For example: a middle age or elderly person who wants to get the best binocular for low light use.
For low light a 7x50 or 8x56 is then often recommended. But if the person's eye pupil dilate to max 5,5mm, a 7x50 will have no gain over a 7x42, or 8x50. The risk is then that he buys a 7x50 in the belief it's better but pays a higher price and gets a larger heavier instrument completely in vain, when a 7x42 of same quality would do the job as good.

 

[Ignatius]

Are there dealers who offer measuring of eye pupil size?​

Probably not but opticians and eye doctors have the necessary equipment (phoropter?)

 

[Thotmosis]

This would be a valuable service. Probably the majority of binocular buyers(and some dealers as well) are ignorant about the the importance of the eye pupil size in relation to exit pupil.
For example: a middle age or elderly person who wants to get the best binocular for low light use.
For low light a 7x50 or 8x56 is then often recommended. But if the person's eye pupil dilate to max 5,5mm, a 7x50 will have no gain over a 7x42, or 8x50. The risk is then that he buys a 7x50 in the belief it's better but pays a higher price and gets a larger heavier instrument completely in vain, when a 7x42 of same quality would do the job as good.

Interesting idea.

 

[Maljunulo]

Just out of idle curiosity, do the pupils react to light the retina cannot detect? (UV or IR)

 

[Vespobuteo]

This would be a valuable service. Probably the majority of binocular buyers(and some dealers as well) are ignorant about the the importance of the eye pupil size in relation to exit pupil.
For example: a middle age or elderly person who wants to get the best binocular for low light use.
For low light a 7x50 or 8x56 is then often recommended. But if the person's eye pupil dilate to max 5,5mm, a 7x50 will have no gain over a 7x42, or 8x50. The risk is then that he buys a 7x50 in the belief it's better but pays a higher price and gets a larger heavier instrument completely in vain, when a 7x42 of same quality would do the job as good.

Or visit the optics store in the evening, when it's dark(er)... I usually do...

It's probably quite common that birders carry too heavy (and expensive) scopes (and binoculars) completely in vain btw...

...for various reasons that is, not only pupil size, or lack there of...

 

[Swedpat]

Just out of idle curiosity, do the pupils react to light the retina cannot detect? (UV or IR)

Interesting question. I have no idea!

 

[PYRTLE]

Answer to the title - no. But an optometrist probably could. It was widely reported on here by many experienced members that as one grows older the exit pupil reduces to c.4mm.......hence an 8 x 32 was deemed a useful all rounder instrument amongst the more mature observer. My eyes are fairly poor due to cataract replacement / macula retinopathy but I still find my Zeiss 7 x 42 useful on occassion, perhaps partly due to the 6mm exit pupil.

 

[NDhunter]

Eye pupil diameter increases in darker light. Hard to measure unless under normal conditions.
What is normal ? Daylight I suppose. Dealers don't do this type of thing, for many that spend
too much time on here your dealer probably knows less about vision and optics and the binoculars
they are selling than you do.

Even an optometrist seldom gets this question. Have you ever had your eyes dilated?
Jerry

 

[SanderBird82]

You can find on internet how small/ big your pupil gets on what age

I know it can be a bit personal. But its that really a big difference?

I am 43. My EP could be 5-6 mm i dark.
Why would i know more exact?

 

[pat mitchel]

assuming that the eye loses the ability to dilate/contract, would not a larger exit pupil still offer an "easier" view (eye placement) WRT to the bino)? Pat

 

[NDhunter]

assuming that the eye loses the ability to dilate/contract, would not a larger exit pupil still offer an "easier" view (eye placement) WRT to the bino)? Pat

You are correct, bigger is better in that respect.
Jerry

 

[Ignatius]

Just out of idle curiosity, do the pupils react to light the retina cannot detect? (UV or IR)

No, which is why you can take a selfie with an IR-converted camera when your pupils are dark adapted. Light up your face with an IR flashlight, hold a steel ruler pressed to your cheek under the eye, and hey presto. Check the image out in your favourite graphics or image editing software, make it full screen, take a caliper to measure the dilated pupil's diameter and then measure that setting off on the ruler in the picture.
FWIW, mine still go up to 6 mm. Or at least they did in Nov. 2020.

 

[Maljunulo]

No, which is why you can take a selfie with an IR-converted camera when your pupils are dark adapted.

Thank you for that.

It wouldn't make very much sense to be otherwise, but I did wonder.

 

[tenex]

Just out of idle curiosity, do the pupils react to light the retina cannot detect? (UV or IR)

(What would be detecting it then?)

 

[wllmspd]

It's probably quite common that birders carry too heavy (and expensive) scopes (and binoculars) completely in vain btw...

...for various reasons that is, not only pupil size, or lack there of...

For binos maybe, there seem to be plenty who seem to only care about observing in twilight, so go for 8x42 over lighter 8x30 that’ll be just as useful in the daytime. Don’t see many people using binos with exit pupils >5mm. I enjoyed a session watching barn owls after sunset with some old 7x50 last year, kept on working nicely well after the camera carrying crowd had left due to “not enough light” ;-)
Spotting scopes exit pupils are never more than 3mm or so, the lower powers needed to maximise it normally resulting in narrower fields of view. I tend to use the scope zoom to give an image that is “nice and contrasty” for the given conditions, so lower powers for duller days.
I should look to give the IR trick a go as I have all the bits I’d need.

 

[Swedpat]

Eye pupil diameter increases in darker light. Hard to measure unless under normal conditions.
What is normal ? Daylight I suppose. Dealers don't do this type of thing, for many that spend
too much time on here your dealer probably knows less about vision and optics and the binoculars
they are selling than you do.

Even an optometrist seldom gets this question. Have you ever had your eyes dilated?
Jerry

No, I have not. I have decided to contact some optometrist to measure my pupil sizes. I don't think the local eyeglasses optician does that so I think I need to contact the hospital.

 

[Maljunulo]

(What would be detecting it then?)

Going way out into left field, I suppose the retina could respond with a signal that the brain wouldn’t interpret as a color but still cause the pupils to contract.

Pure off-the-wall speculation.

The answer to the original question was “no”.

I can’t think of any way such an arrangement would benefit the organism.

 

[NDhunter]

The eye pupil adjusts its diameter to the level of light. It opens when it is dark to let more light
in, and closes under bright light. Think about how an SLR camera lens does it. It is a diaphragm.
Color has nothing to do with it.
Jerry

 

[Maljunulo]

I think, in the US, only an ophthalmologist is allowed to dilate your eyes.

 

[Ignatius]

I think, in the US, only an ophthalmologist is allowed to dilate your eyes.

Some women do that too.

(Apparently oxytocin can dilate the pupils, and that is released when you look at the object of your desire.)