Prescribing Aniseikonia

Why does adjusting the BC to increase mag work the best for a plus lens?

increased BC would also increased the VD, in which both would increase the mag for a plus lens, but for a minus, increasing the VD decreases mag so the two factors work against each other

When must you always specify BC and CT?

for any hyperopic aniso, even if just one eye is hyperopic

Why must you specify BC and CT for hyperopic aniso?

standard lens design will work against you, higher plus lens will always have steeper BC and thicker CT, making it even more magnified

If you are ordering first time aniso rx, what should you recommend frame wise?

smaller eye size

shorter VD

If an aniso patient is unhappy with equal BC + CT, what should you do?

consider decreasing aniso correction

eikonic lens design

What are the two ways to determine the ideal magnification for an eikonic lens design?

1. through image size testing/afocal magnifiers

2. based on spec Rx

When eikonic lens design doesn't help, what are the options for aniseikonic patients?

monocular blur by:

dioptric blur

bangerter foils

fresnel prism

dioptric blur

Why does monocular blur work for Aniseikonic patients?

decreases central vision but has minimal peripheral effects, therefore allowing peripheral fusion + normal field of view