So sa tingin ko you have two choices.
ilimit mo ang playtime at mag pahinga ka for at least 15 min. after a few hours from gaming
OR
buy a pair of glasses di naman kelangan Gunnar as long as it has the same technology to protect your eyes lets say... proprietary tints and coatings that block high-energy blue light, UV and glare.
Check mo maga articles dito
http://www.gunnars.com/category/science/blue-light-vision/
not sure if Gunnar has prescriptions kaso if wala then no choice but to look somewhere else kase walang grado ang Gunnar Glasses by default and they are strictly to be used while looking at screens otherwise ma sisira lang ang maga mata mo at ma force kang mag salamin na may grado

.