An eye that can see far away object clearly but which can’ t clearly focus on objects that are 25 cm from the lens of the eye is farsighted or hyperoptic. The near point for such eye is farther than 25 cm from the eye. Correction is done using a converging lens that images an object at the normal near point to the person’s larger than normal
near point.
An eye that can see objects at a normal near point of 25 cm but has a far point that is smaller than very far away at infinity is nearsighted or myopic. The far point of such an
eye is closer than infinity. Correction is done using a diverging lens that images an object that is very far away to the persons small than normal far point.
To do
Use the application to investigate a normal eye for an object from the normal near point to the far point.
Use the application to investigate a farsighted eye for an object from the normal near point to the far point.
Explain how the corrective lens works for a farsighted eye.
Use the application to investigate a nearsighted eye for an object from the normal near point to the far point.
Explain how the corrective lens works for near sighted eye..
Use Excel to set up calculations for a corrective lens of a person’s eye. Inputs are the near point distance, the far point distance and the distance of the lens from the eye
to be corrected. Outputs are the power in diopters of the required corrective lens. Plan on making two sheets in the Excel file – one sheet for a farsighted eye, and
another sheet for a near sighted eye.
Assuming an index of refraction of 1.42 for the lens, draw a one – to – one lens that.
Has a power of 3.4D.
Has a power of – 2.5 D.