Diopters, Aberration, and the Human Eye | Geometric optics | Physics | Khan Academy

[@sarahholland5980]

how cool and so well taught!! nice to finally be able to apply something in E&M to real life since most of it is so abstract. thank you guys so much for this playlist, 3 days is an insane speed to have to learn this stuff at in time for the final but was totally doable with your help!

[@alejandrocanas6744]

This videos is JAM PACKED with MCAT content, like no lie. This is exactly how they test optics. Nice presentation. :D

[@normadicn5700]

Yeah. It's certainly amazing

[@Silent_Sounds]

beginning of the video quite literally says it's in collaboration with the AAMC, who makes the MCAT.

[@surendersingal2192]

Very revealing visual explanation. Thank you

[@xxthunderbird46xx]

Very well explained. The illustrations help ALOT. Great review.

[@DanielC-ck2ds]

best explanation for diopters, thank you so much

[@victoriabiris1959]

This was really helpful, thank you so much!!

[@rahfmorad2309]

I can't thank you enough ❤

[@Its_bulma]

Best explanation😊

[@makhanlalkar3111]

Thank you sir!!! It really helped me!!

[@edogz8646]

Great explanations of optics! Thank you

[@darrenchahal2245]

how chromatic abberation is corrected in human eye?

[@opjang0320]

Awesome video to me who is Korean optician. thank you for video

[@Violenzz]

Awesome, thank you :) well explained

[@lisasolomey6334]

Thank you!

[@koondoog4282]

why did he draw the rays at around 9:50 radiating outwards and then through the focal point, shouldn't they just go through the focal point?

[@terachith1565]

is convergent of both eye as a reflex to near objects reduce that abberation and how ?

[@vinayseth1114]

Wow! I remember using the formula 1/f=1/v-1/u a lot in 12th grade, but never once did I question the significance of 1/f ! It's amazing how much many of us sail through the school curriculum without even asking the basic questions. Thanks for this-very helpful!

[@vinayseth1114]

So why do the focal aberration and the chromatic aberration not take place in the human eye, even though the pupil is also a spherical lens?!

[@crawford323]

You have ask the million dollar question. I have pondered this in my mind for a long time. I have always assumed the coatings on the camera lens as well on microscope lenses affect the transmissibility of the light and ( this is where I may be wrong) correct chromatic aberrations. It’s a big deal and lens manufacturers jump through hoops designing lenses which reduce this. A sensor or piece of film is more or less flat. So how do lens manufactures make all the color spectrum focus at a single point? I do not know precisely. What I do say I know is the simple biological lens does not have such coatings nor complexity. The retina is curved which helps achieve easier focus in that the biological eye does therefore not have to deal with edge sharpness. This is where a manufactured lens has trouble keeping the center plus the edge of flat art the same sharpness. Smaller aperture help this by bringing the light through the center of the lens so the bending is reduced. Perhaps another assumption of mine. Nevertheless the challenge to get all of the spectrum focused at one point is great. How does the biological eye do it? I think snd I do not know this to be correct. In fact I questioned a doctor about this and he had no time for me. My guess is ( again I may be wrong) is the color receptors in the biological eye is actually at different levels on a microscopically. Mere microns if distance difference could allow the difference wave lengths to be captured at its natural focus point. My educated doctor told me that was ridiculous and that the brain brings it all into focus. Ummmmmmmm not so easy magic man. To reconstruct the circles of confusion ( where and out of focus point of light becomes not a point but spherical. I think this gets further complicated by the light refracting due to the aperture blades.) which is a physics issue. If the brain has the power to reconstruct a circular blob of light back to a the finest point, you can eat my hat! The easiest thing to do would be to evolve and have the receptors for the different colors at the point of natural focus for this colors. So now I have a headache once again thinking about this exact thing. Also note that no one has answered your question which claims to know. I certainly do not. You and I might be genius’s just asking this question. How does the biological eye deal with all these different types of abbreviations? Certainly a curved sensor array helps but is it that easy? Don’t know.

[@Fireneedsair]

The pupil is not a lens

[@randompenguin6376]

How do I solve a problem where I have to find how many times the image has been shrinked and I have the lense power and object distance given but no focal length and image distance given? It's a concave lense with -7.5 dpt and the object is 40cm from the lense. HELPPP

[@normadicn5700]

Check magnification in lenses

[@Fireneedsair]

Can you do a video on a concave lense?

[@Fireneedsair]

Disregard

[@maciejjurczak7258]

why in short-sightness you see picture as blurry not as bigger?

[@vinayseth1114]

1:35 So what would a person see through such a lens where light gets bent at infinity? Just an opaque lens, I suppose?

[@ockertoustesizem1234]

it would look normal through the lense because the light isnt being bent at all

[@Silent_Sounds]

@@ockertoustesizem1234 light being bent is what focuses and creates the clear image. With a lens barely bending any light, the image projected onto your retina would be indescribably blurry. Idk how accurate this is, but I think you'd basically just see one color for all of your vision. Maybe a gradient but not much more than that

[@ockertoustesizem1234]

@@Silent_Sounds the guy was talking about looking through a lense like putting on glasses. i already know everything you just said

[@mithiahmed0101]

How is power in concave lens?

[@akshatsharma2537]

if the power is more the lens will be more thick

[@acousticnext2564]

There's a couple of mistakes in this video though. The major one being that the focal point is in front of the retina (virtually) instead of on the retina.

[@CandidZulu]

If u put a lens infront of the eye, wont that put a right sided image on the fovea, so then when the brain flios it one more tie u see the world upsidedown? ;)

[@umarshahzad9805]

Thank You Sir

[@doctoraasem6399]

thanks alot, I has benefit very much .

[@sandrisvirsis6776]

I see blue and red lines

[@SolacePiano]

Eye hate physics..

[@richardhassan6307]

I see what you did there😂👌

[@vineethvenugopal8613]

😂😂

[@vineethvenugopal8613]

Eye understand what you mean

[@nayeemrifath2809]

Sir, I need a lecture about lens maker equation...

[@mdtoufiquzzaman9118]

Nayeem Rifath Ah I dont think you will find the lens maker formula here. Try a different site for this.

[@GB-mt8mj]

So you said that near sighted need a diverging lens and said they need a concave lens. I though concave was converging and convex was diverging.

[@tapirai4593]

Gavin Brion u are talking about concave and convex mirror

[@TheOsamaBinLiner]

Concave diverges Convex converges

[@DD-gi6kx]

your explanation of bigger lens makers absolutely no sense, you drew the two lenses to look the same but if they were the same diameter, then the one with shorter F.L/higher power, will be thicker in the middle so it will actually be a bigger lens, so the bigger lens is higher power...suggesting a lens is bigger cause it has a longer FL is really what makes no sense