Brightness flickering on Lenovo Yoga 720 | Ubuntu 18.04

I have a Lenovo Yoga 720 and am running Ubuntu 18.04. The screen changes brightness automatically every 5-10 sec. This does not happen with Ubuntu 17 or Windows 10 (dual boot). Please assist.

description: Convertible
product: 81C3 (LENOVO_MT_81C3_BU_idea_FM_YOGA 720-13IKB)
vendor: LENOVO
version: Lenovo YOGA 720-13IKB
serial: MP1CHKDC
width: 64 bits
capabilities: smbios-3.0 dmi-3.0 smp vsyscall32

This may be caused by the adaptive brightness setting. I had the same issue. It's way too aggressive for my preferences.

Go to Settings > Power then turn automatic brightness off