DS is on his 5th prescription (but 7th pair of glasses) in 2 years! the optician said that because of his age (14) and growing so fast etc his prescription has changed alot but he has also broken two pairs, one when a basketball hit him in the face and once when a friend caught him in the face when going to point at something!!! I always take his and DH prescription on holiday with me as well, because they wear them all the time it would be a disaster if they were to break whilst out of the country, thankfully I have not had to use it though