But new Johns Hopkins research in mice suggests that neural stem cells, the bodyâs source of new brain cells, are resistant to radiation, and can be roused from a hibernation-like state to reproduce and generate new cells able to migrate, replace injured cells and potentially restore lost function.
Pupillary Distance (PD) You'll need to know your PD if you want to order glasses from EyeBuyDirect. Don't worry if your glasses prescription doesn't include your PD, we can show you how to measure it by yourself. How to measure your pd
1 Make sure you measure eyeglasses lens properly because it is what will determine the fit of the frame on the glasses on your face. 2  You don't want the eyeglasses frames to be too small or too big, but you want the frame to fit just right on your face. 3  Measure the lens height. The lens height will give you a general idea of the fit of the lens over your eye. 2  When you measure eyeglasses lens height it will help you to see how narrow or tall your lens height is, and can help you find adequate frames that suite you when you order online.