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
PD stands for pupillary distance which simply means the distance between your pupils. In order for our glasses to perform at their best, we need to create prescription eyeglass lenses that can match the distance between your eyes, so the center of each lens aligns with the center of your pupils. For this reason, we need your pupillary distance measurement â also known as the PD measurement.