Island lights are a wonderful way to spruce up your kitchen / dining room. They will be an eye-catcher in the room and a great conversation piece! But don't let them hang so low that they are blocking these conversations with your guests. Yes, good lighting is important in the kitchen so you can see while you cook up a storm. All hanging lighting should be 30-36 inches above countertop or tabletop surfaces.
If your kitchen is part of an open-concept space, avoid big chunky fixtures that can get in the line of vision and go for glass fixtures that allow you to see through them while allowing the space to appear to remain open.