Those are for your light amplification googles. The one you find in the very first level (in the crate in the room with the 'goink' droid and the elevator that takes you to a very dark room). You require the googles when you step off the cart into a dark mineshaft, slightly lid by the green crystals.
Remember that you (should) have two googles. One that has a blue light and one that has an orange light. With the orange one you can still shoot, with the blue one you can zoom in and out (when pressing the fire button or alternate fire). Use the orange one in the mineshaft.
"Continue to research and develop new and more powerful starships and weapons to inspire fear in resistand systems" The Tarkin Doctrine, Imperial Communique #001044.92v