If you’ve been curious to try computer glasses, but were scared off by the sky-high price of Gunnars, Velocifire will sell you a set for $12 today with promo code GPPYKYNX. If you aren’t familiar, the appeal of these things is that they block out the blue light that emanates from the screens we stare at all day, which can cause eyestrain, headaches, and even insomnia. They do not, however, block Twitter, which can cause the same symptoms.