Following
bilateral cataract operation, a patient has a post-operative refraction
as follow:
OD -4.00DS
6/6 Add +2.50 DS N5
OS -0.50DS
6/6 Add +2.50 DS N5
She does not appear to be troubled by aneisokonia.
However, when reading through her new executive bifocal glasses, she complains
of vertical diplopia.
a. Examination reveals that she reads 0.6 cm
below the optical centre of the
reading section. What is
the induced prism in the reading positions?
b. Suggest ways of reducing this prismatic
effects. |