Apple har ibland fått kritik för att de valde glas i skärmen till iPhone. I iPhone 4 har de använt samma sorts glas som sitter i helikoptrar och på höghastighetståg:

"All the breakthrough technology in iPhone 4 is situated between two glossy panels of aluminosilicate glass - the same type of glass used in the windshields of helicopters and high-speed trains. Chemically strengthened to be 20 times stiffer and 30 times harder than plastic, the glass is ultradurable and more scratch resistant than ever. It's also recyclable."