Waking up in the morning and wiping away the crusty yellow gunk from around our eyes is part of everyday life for most of us but have you ever wondered what the substance – sometimes known as ‘sleep’ – actually is? The flaky crust that is typically found in the inner corner of the eyes is officially called rheum but many will know it by nicknames such as ‘sleep’, ‘sleepy dust’, ‘eye gunk’ or ‘eye crust’ to name but a few. Scientist explains what the crusty ‘sleep’ in your eyes actually isIn a video posted to TikTok via @huberman.clipss, neuroscientist and podcaster Andrew Huberman revealed wha…