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
The distance between the centre of one pupil to the centre of the other pupil is the PD. Prescription glasses are made so that the distance between the optical centres of the glassesâ lenses, is the same as your PD. Once you are an adult, your PD does not change but PD varies from person to person.