I bought these glasses for my 5 year old.  My 10 year old daughters were having a Harry Potter birthday party, and he wanted to be Harry.  They fit him fine, but they are more on the snug side (as far as the width).  I would say he has an average sized head for a 5 year old.  We've had them for 3 months, and he's worn them a lot with the robe I made him.  They seem to hold up well.  They are plastic, though, and will break if forced.  They are made of a nice plastic that does give some, but they aren't super pliable.  These would be great for a Harry costume.  The tape is actual fabric medical tape, so they are very authentic looking.  I also bought him the plastic light up wand that makes sound, and he loves it (worth the $5 I paid)!  His imagination really runs wild when he's wearing his Harry costume.  I would not recommend these glasses for anyone over age 6 unless they have a small head, but what's funny is that the package states they are not for anyone under age 12 or 14 (I can't remember, but it was quite funny).  I have a small head and can put them on, but they are very tight on the sides and may break over time from the stress of a larger head.  They would probably work just fine for a one time costume for an older child, though.