How are we able to view close up objects given f=0.02?

[zut212]

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I never could understand how a normal person with healthy eyes is able to view a close-up object. To highlight my confusion, here is an example:
f = +0.02 m
the retina is circular, and it is 0.02m behind the iris, and it is able to bend a little bit (visual accommodation).

o = INFINITY --> This image shows up just fine. No accommodation is required here.

o=0.05 --> i = 0.0333. How does the retina "bend" by 1.333 cm? I don't understand how the eyes can see this close-up object. Please help.

o=0.04 --> i = 0.04. How does the retina "bend" by 2.000 cm? I don't understand how the eyes can see this close-up object. Please help.

o=0.02 --> i = INFINITY. However, I don't notice anything like this when an object is 2 cm from my eyeball. Please explain.

 

[zut212]

When I put my finger directly in front of my eyes - the o=0.01. However, given that f=0.02, the image is formed at i= -0.02 . I don't understand this bit at all either.

 

[PiBond]

When I put my finger directly in front of my eyes - the o=0.01. However, given that f=0.02, the image is formed at i= -0.02 . I don't understand this bit at all either.

that means that the image is out of focus since the object image is focused behind your retina.

 

[PiBond]

for your original post, it is my understanding that in order to keep near objects in focus the lens must be rounded (through accommodation, as you said) in order to increase the angle of refraction. making this lens more convex causes the light rays to converge on the retina instead of behind it and thus allows the object to come into focus.

i remember seeing somewhere that the human eye cannot effectively focus on objects closer than about 8-10cm and this only gets worse with age. maybe someone can check my facts for me