The skill of applying eyeliner can be improved by training but many of the girls find it troublesome to do this on their own. It needs a lot of experience to apply it correctly and make the both eyes look the same. Because the strokes applied by eyeliner may have a changing width which is hard to draw without enough skill. Easyliner is a concept of an eyeliner that solves this problem. It scans the length of one's eye using an infra red laser diode (the same sensor used on laser mice) and then applies different kinds of styles that can be chosen from a catalog for all kinds of eyes, since it can draw the strokes based on the length of the eye boundary.
So there is no need for extra attention, just select the pattern scan the upper eyelid one time and then applies the eyeliner
you can be sure that both eyes will look the same because the line with and the patterns are applied automatically.