You should probably have your I-Phone handy the next time you go shopping at your local beauty supply store.  This is so you can do your research as you shop.  It is important to buy products that are manufactured in USA inspected facilities.  Products made outside of the United States may or may not be produced with the same quality control as those produced in the United States.  This is especially important when it comes to the cosmetics you purchase, including eyelash extension adhesive.  Many products make their way to USA shelves deceptively marketed as American made.  On this link you can check the best eyelashes extension on the entire USA. 

Using a pencil, pen or makeup brush look into a mirror and place your tool from the inner corer of the eye to the outside edge which will let you measure your eye. Technically you should be able to fit the width of one of your eyes perfectly in between the two eyes. When you get overlap (i.e. there’s less than one eyeball width space apart) you tend to have close-set eyes so you want to create the illusion of drawing them apart with lashes that are longer at the outer corners. If the space is bigger than one eyeball width then you have wide-set eyes and want the emphasis to be towards the center and inner corner of the lashes to draw the eyes together.