A Snellen chart (below) may just look like random letters in different sizes, but they were carefully designed to measure visual acuity. This piece on testing the limits of human vision brings it all into focus.
Fun fact: most ophthalmologists have switched to a LogMAR chart (below):
• Testing the limits of human vision (YouTube / Verge Science)
Wikimedia images: LogMAR and Snellen
Anthony Gulino writes, "Los Anarchists Junior Derby is a nonprofit that takes a DIY approach to teaching roller derby to kids. It runs programs for all levels from the youngest, newest skaters to the highest level of competitive junior derby at its dedicated facility, Anarchy Hall, in Sun Valley, CA. Los Anarchists' travel team is […]
Every year around this time, our friends at Sparrow Lockpicks (previously) come out with a incredibly clever, giftable addition to your locksport arsenal; I always buy a few of these for Christmas gifts (often for younger people on my list) and they're universally well received.
20 years ago, Illinois was rocked by a scandal after the widespread practice of locking schoolchildren, especially those with disabilities or special needs, in small, confining boxes was revealed. The teachers who imprisoned these children argued that they did so out of the interests of safety -- that of the imprisoned students, of the other […]
Weighted blankets are officially a thing. And if you’ve ever tried one, you know there’s a reason for the fuss. Parents have known for generations that swaddling a baby has a profound calming effect, and the gentle pressure that blanket weights provide can have the same effect on restless sleepers. Pretty much all parts of […]
Walk through any office, and you will likely spot a few bobbleheads. These wobbly figurines are great fun to have around, although most celebrate people we will never meet. For something a little more personal, try Handmade Custom Bobbleheads. These mini caricatures are sculpted and painted by skilled artisans, based on any photo you provide. […]
In the early days of the web, everyone wanted a .com domain for their site. As a result, all the good ones got snapped up. But .com no longer has the cachet it once did. In fact, many new businesses and individuals are opting for other top-level domain extensions. One of the most memorable is […]