I learnt about far Point of a myopic eye and near point of a hypermetropic eye. But I am confused about the above question. And if near point is defined for a myopic eye and far point defined for a hypermetropic eye, do they have a significance?
[Physics] Is near point defined for a theopic eye and far point defined for a hypermetropic eye
opticsvision
Best Answer
You're overthinking the theory. Think practically and the answer is obvious.
The standard eyeball has a crystalline lense whose focal length is varied by the ciliary muscles. The maximum and minimum accommodation of focal length is what determines far point and near point respectively.
The near point and far point have to be regarded as properties of the eyeball and not as properties of the defects (this is where you were confused)
For practical purposes, for myopic eyes, we only need to know the far point and for hypermetropic eyes, we only need to know the near point. For presbyopic eyes, whose crystalline lenses are less flexible, both far point and near point are relevant.
Remember that this information is needed to calculate the focal length of the required correctional lense (ie, spectacle lens).