To fit a contact lens to a patient\'s eye, a keratometer can be used to measure

Question

To fit a contact lens to a patient's eye, a keratometer can be used to measure the curvature of the cornea-the front surface of the eye. This instrument places an illuminated object of known size at a known distance p from the cornea, which then reflects some light from the object, forming an image of it. The magnification M of the image is measured by using a small viewing telescope that allows a comparison of the image formed by the cornea with a second calibrated image projected into the field of view by a prism arrangement. Determine the radius of curvature of the cornea when p = 26.0 cm and M = 0.0170. mm

Explanation / Answer

help: M = -q / p and the second equation is the mirrior equation which is: 1/p + 1/q = 2/R R is the radius of curvature, and q is the image distance. First step is to solve for q, which is: q = -M*p Next, you can plug p and q into the mirror equation and solve for R. R = 2/ (1/p + 1/q) just place your values and get answer.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---