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
Your PD (pupillary distance) is the distance between the centre of your pupils, measured in millimetres. Your Optician will measure this during your sight test although it is unlikely to be written on your prescription. However, you can ask your optician for your pupil distance following your test.