I suspect it still won't work properly. It might help, simply by the way of dimming the light in the center so the light to the sides looks a little more bright by comparison. If you want to get to the ultimate design, then you'll have to mould the buttons so that they properly carry the beam of light and distribute it, by way of something prism-like, or a channel like with fibre cabling, within the extremes of the button. A level of physics I can't help with.

Bruno