His eyes are blue and his hair is brown, dyed blonde. He usually wears a suit.
Lynden always wanted to be a Healer, looking after sick animals and sick children in his classes from a very young age, and trained hard to become one of the St Mungo's Healers all his life. He also considered animal care but then decided humans were more important, choosing to spend time as a student participating in extra first aid classes. he would spend hours in the Hospital Wing simply observing what was happening there during his lunch breaks and even during half terms when he had no need to remain at Hogwarts. In the summer holidays he would often go to St Mungo's to observe as well but of course they were more strict there.
As soon as he left Hogwarts he participated in a three year training course and joined the St Mungo's Healers fairly soon after he had finished his training. Once he had a fair amount of experience, he was promoted to treating muggles who had been exposed to magic in a muggle hospital and then he progressed to healing in Azkaban prison. He is also a Healer for Hogwarts during the times when Madam Pomfrey is unable to be there.