Biomedical Engineering Reference
In-Depth Information
5. A hyperopic eye is corrected with a
6.00 D lens in the spectacle plane. Assum-
ing a vertex distance of 12.00 mm, how much accommodation is required to view
an object at a distance of 10.00 cm from the eye?
6. A 5.00 D myopic eye, as measured in the spectacle plane, views an object through
a
+
4.00 D lens held 10 cm in front of the eye. If the object is 15 cm from the eye,
how much accommodation is required for the image to be focused on the retina?
(Assume that the spectacle plane is at a distance of 1.3 cm.)
7. A 45-year-old patient is corrected in each eye with a -6.00 D spectacle lens.
The patient undergoes LASIK, which fully corrects the ametropia. (a) Prior to
the surgery, how much accommodation is required to view an object located
20.00 cm from the cornea when the patient is wearing his spectacles? (Assume a
vertex distance of 15.0 mm.) (b) Following the surgery, how much accommoda-
tion is required to view this same object? (c) What is the clinical significance of
this finding?
−
