I throw them into a chest and forget about them. When the chest fills up, I find or build an empty chest and start filling that one up. The storage room in one of my main buildings has a good supply of them. In my current game, I'm torturing myself by not using portals at all and building transportation networks (trails, paved roads, and ferry ports) instead, so one of the main uses for eyes is eliminated. I've built lots of empty shells of unnecessary buildings all over the place. Right now, most of them just have a fire, a bed, and a couple chests, but I have plans for them. When/if I get around to furnishing and decorating them, I'm sure I will add lots of normal and blue torches, and the resin and eyes will start to get used. Of course, supplies in one area are likely to get depleted while I have a surplus somewhere else, so I will be dragging carts full of eyes and resin down the roads I have been building. Eventually, I'll get sick of it and play other games until the next big update comes out, and I'll start all over again with a new accumulation of eyes and resin.