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 Measure the distance between the two dots on your lenses with a millimeter ruler. 2  That's your distance PD. 3  If you need a near PD for reading or computer glasses, just do the same procedure but focus instead on the object you will be looking at, either reading material or computer monitor.