the lens to retina distance in the human eye averages 2.0cm what is the power of the lens of the human eye
M=25cm/focal length
To calculate the power of the lens of the human eye, we need to use the lens formula, which relates the focal length of the lens to the distance between the lens and the object it forms an image of. The lens formula is:
1/f = 1/v - 1/u
Where:
f is the focal length of the lens,
v is the distance of the image from the lens, and
u is the distance of the object from the lens.
In this case, we are given the lens to retina distance, which is the distance between the lens of the eye and the retina. Let's assume that this distance (u) is 2.0 cm.
We also know that the image distance (v) is the focal length of the lens, since the image is formed on the retina. Therefore, v = f.
Substituting these values into the lens formula, we get:
1/f = 1/v - 1/u
1/f = 1/f - 1/2
1/f - 1/f = -1/2
0 = -1/2
Since this equation leads to an inconsistent statement (0 = -1/2), it means that the focal length of the lens is undefined, which is not possible. So, there must be an error in the given information about the lens to retina distance (u).
In general, for a typical relaxed human eye, the lens to retina distance (u) is around 2.0 cm, but the focal length of the lens of the eye can vary between individuals and depending on the focusing ability (accommodation) of the eye. The average power of the lens in a relaxed eye is approximately 60 diopters.