Mar 08 2014

Miosis and Mydriasis Mnemonic

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. <>.
“Mydriasis.” Merriam-Webster. Merriam-Webster, n.d. Web. 07 Mar. 2014. <>.

1 comment

  1. I am sure every 3rd & 4th year Med student knows this on but in case there is one resident out there who was just too tired to teach it to you I will. The eyes OS & OD.

    I was taught to remember them like this…thinking of a husband talking to his wife…& you know the wife is always correct (or she likes to think she is ?)

    Oh Dear, (OD) you’re RIGHT!

    So Oculus Dexter OD = R
    Oculus Sinister OS = L
    Occlusion Uterque OU = BOTH EYES

    One more word of advice. I finished medical school and did my residency and practiced. If you are going into OPHTHALMOLOGY learn how to spell it. There is an H after the P & the T. It’s not Opth it’s ophth. Got it?!
    When you go to your interview and you fail to get a spot there bcz you can’t spell the profession you want to spend the rest of your life practicing, it’s just a shame. It happened to a great guy friend of mine who just was nervous and had his top place his first interview. They asked him to spell Ophthalmology and he forgot the first H. They didn’t even let him finish the interview. I told him he didn’t want to be there anyway, if they were that rude. Just a warning.

    A couple of these definitions were taken from by David E Vollman, M.D, MBA

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