Sure, you can get bifocal lenses where the top is for far away and the bottom is for computer distance. But unless you hold your reading at the same distance from your eyes as your computer screen, they won't work for close up very well.
Piercing your skin with a bunch of tiny little needles, may not sound appealing at first, but do the cosmetic benefits of the dermaroller outweigh the negative? At first glance, a derma roller may appear to a miniature barbaric torture device, but it has in fact become one of the most innovative approaches to skincare treatment in years. Whilst the science behind derma roller is not impressive, the results are apparent. Perhaps not for wrinkles or signs of aging.
The rollers exert force on the work, and the work exerts force on the rollers. The rollers and the work-piece exert force on each other, and if either is absent, there is no force on either. The rollers exert force on the mill frame at their bearing points. There is no benefit to trying to make a distinction between who presses on who as it does not change what happens nor does it change the design of the rolling mill. What is important is that the rollers are doing work to the work-piece. The rollers are driven and the work-piece is dragged through by friction.