Flip Up Helmets Flip Face Helmets - How Are They

Flip Face Helmets - How are they - flip up helmets

I recently came into the world of motorcycle racing for 30 years and only buy a bike. Now I need a helmet. I realized today helmets are above, where you can open the visor on his head. How do they compare with full-face helmets? What if I bite into the grass face first? What is there to cover when it reaches the ground?