Try to work in the daytime, rest in the evening if possible - it is better for the eyes, as well.
Don't forget to wear comfortable clothes and gloves too. http://creativefloralsjupiter.com/__media__/js/netsoltrademark.php?d=wq.xigu.ren%2Fhome.php%3Fmod%3Dspace%26uid%3D530117