Assume I have some contact eye lenses which I covered with black color, so they're not transparent anymore. Then I made a tiny hole at the center of each eye lens. What kind of an image will I see if I put them on? Will it be upside-down image like camera obscura does? Will it be blurry?
$\begingroup$
$\endgroup$
1
-
$\begingroup$ Related: Why do images not appear inverted when looking directly through a pinhole camera? $\endgroup$– benrgCommented Mar 14, 2022 at 15:41
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
6
It will be dim and, assuming the eye lens is itself working ok, quite sharp. (If the eye lens is poor then the pinhole tends to sharpen the image, but to make it sharper you need a smaller pinhole, and then it gets even dimmer).
The image falling on the retina of your eye will be upside down. However, using the normal eye lens this also gives an upside-down image on the retina. The neurons of the brain then interpret this and deliver to your conscious perception the result after correcting for this, i.e. the right way up. So with the pinhole the same will happen: on your retina the image is upside down, but to your conscious perception the image is the right way up.
answered Mar 14, 2022 at 12:08
-
$\begingroup$ So the biological eye lense will not revert the reverted image made by a 'plastic' eye lense? $\endgroup$ Commented Mar 14, 2022 at 12:13
-
$\begingroup$ @ЕвгенийПавлов sorry I don't understand your comment question $\endgroup$ Commented Mar 14, 2022 at 12:36
-
$\begingroup$ I mean that image on the retina is "upside-down" because of the biological eye lense inside an eyeball. But we also have contact eye lense (as question states) with a tiny hole that should act like camera-obscura and it's also have "upside-down" effect. So we have double upside-down effect. That means the image on the retina should be as it is. That mean our brain should percept it as upside down image. $\endgroup$ Commented Mar 14, 2022 at 13:02
-
$\begingroup$ I see. No there is no double-reverse effect. The combination of 'pinhole + lens' is just the same as a lens of very small width. The reversal is not an effect of either a pinhole or a lens on its own, it is rather an overall effect of the journey of light rays from source to image. Try drawing a ray diagram (or find out more about such diagrams) to see this. $\endgroup$ Commented Mar 14, 2022 at 14:01
-
2$\begingroup$ My understanding of the question is that the pinhole is in front of the eye's lens, not replacing it, so the image won't be blurry. It will be sharper if anything. (en.wikipedia.org/wiki/Pinhole_occluder, en.wikipedia.org/wiki/Pinhole_glasses) $\endgroup$– benrgCommented Mar 14, 2022 at 15:39