There are only a few high yield ophthalmology topics on the boards, and distinguishing pupil size is one of them. Keeping the medical terms straight for constriction and dilation of the pupil can be difficult.
Here is a mnemonic to help:
MIosis is pInpoint pupils
MyDriasis is Dilated pupils
“Miosis.” Merriam-Webster. Merriam-Webster, n.d. Web. 07 Mar. 2014. <http://www.merriam-webster.com/dictionary/miosis>.
“Mydriasis.” Merriam-Webster. Merriam-Webster, n.d. Web. 07 Mar. 2014. <http://www.merriam-webster.com/dictionary/mydriasis>.