Exactly 200 years ago, a French engineer introduced an idea that would quantify the universe’s inexorable slide into decay. But entropy, as it’s currently understood, is less a fact about the world ...

The pupillary distance (PD) measurement is a requirement for people who want to purchase eyeglasses. Here, find out how to measure your PD using a mirror and a ruler. Share on Pinterest Some eyewear ...

In today’s data rich environments, it can be tempting to measure broadly, then cherry-pick the results that seem most compelling. But just because data are widely available doesn’t mean everything is ...

Pupillary distance helps center your eyeglasses prescription. Your eyeglasses provider normally measures it for you, but you won’t find it on your prescription. If you order glasses online, you’ll ...

BMI is still commonly used to assess obesity even though research has shown it's not necessarily a reliable metric. A new study proposes doctors instead use technology that can measure body fat. Body ...

There are many different factors that determine how a watch fits on your wrist. The most common indicator of a watch’s size, and the one most people use when shopping for a watch, is the case size.

Pupillary distance is the space — measured in millimeters (mm) — from the center of one pupil to another. When you need glasses, an optometrist or an optician will measure this distance to make sure ...