Many times when you’re working on a Photoshop document that has many layers, you want to see just one layer at a time. It’s a pain to turn off all the other layers, especially if you don’t use Layer Groups. You can quickly turn off all but the one layer you want by holding down the Option key and clicking on the eyeball next to the layer you want to see – all the other layers will automatically hide. To get all your layers turned back on, simply repeat the process.