I have a right hyperphoria, and my optometrist prescribed me vertical prism that is 1/2 BU on the right eye, and 1 1/2 BD on left eye.
My question is: if it is my right eye that turns upwards, why is it that the base down prism is over my left eye? Of course, I'm assuming that base down prisms shift the image downwards, and vice versa for base up prisms. Please correct my understanding if it is wrong.
Thanks.