Up to what age can one do phosphenes?
It all depends on the health of your eyes; you need to ask for advice from your doctor or your ophthalmologist. Up until the day before his death, Dr. Lefebure was able to demonstrate that he could read texts in small print at arm’s length without glasses. Further proof, if need be, of the incredible beneficial effect of phosphenes on the health of the eyes (on condition, of course, that one respects the rules set for lighting, as he set forth in Phosphenic Mixing in Education). And furthermore, throughout his entire life he never wore glasses!
