The Qur'an and hadith very accurately stated, that we must wash our hands and maintain personal hygiene. However, in the West, prior to Germ theory, people believed you only got sick due to bad air. For toilets, they would go and poop in a bucket and have a slave throw it out the window, sometimes it would fall on someone's head: someone who was walking outside. The river Thames, today the cleanest river, used to be brown because of all the poo in it! They did not start washing hands until the 19th century! They did not start brushing their teeth until the end of the 17th century, whereas Muslims started Sewak.
An idea of a spherical Earth was introduced in the 6th century (BC). However, the Christians burned any books that said the Earth was flat, or that the Sun was at the center of the universe, because it was blasphemy to them. However, at the same time, Muslims were prospering in a Golden age of science and medicine.