If you're wearing contacts, you might want to take a look at this.

We're conducting a survey of our viewers! If you have time, please give us feedback:

Hosted by:
----------
Support SciShow by becoming a patron on Patreon:
----------
Dooblydoo thanks go to the following Patreon supporters: Kevin Bealer, Mark Terrio-Cameron, KatieMarie Magnone, Inerri, D.A. Noe, Charles Southerland, Fatima Iqbal,
سلطان الخليفي, Nicholas Smith, Tim Curwick, Scott Satovsky Jr, Philippe von Bergen, Bella Nash, Chris Peters, Patrick D. Ashmore, Piya Shedden, Charles George
----------
Looking for SciShow elsewhere on the internet?
Facebook:
Twitter:
Tumblr:
Instagram:
----------
Sources:











(99)00027-5/fulltext