Some attributes will affect skills even if they aren't used in skill calculations. For instance, you will fumble more attacks if your dexterity is low even if you are using spears with high spear skill. Eyesight may or may not affect how well you hit with ranged attacks (devs are purposefully mysterious about this sort of thing I think) although I think it is more that javelins are more short to medium ranged weapons. I don't think people in general are going to be precise that often throwing a stick at a moving target 16-40m away. I try to use javelins within 5 tiles, 8 if i'm really pushing it.