Glitch

Im not sure whether this has happend to anyone else apart from me but when i load a world or go on a server, a really crazy render glitch happens which makes blocks spaz out and change colours. Heres a picture: https://gyazo.com/80c6c10888b82a4d286d6721b830a11c
Please help me out, i have no idea why this happens.
Thanks,
~Vitani