Optical coating refers to the application of thin layers of material on the surface of optical components, such as lenses and mirrors. These coatings enhance the performance of optical devices by controlling the reflection, transmission, and absorption of light. Common types of coatings include anti-reflective coatings, which reduce glare, and reflective coatings, which improve light reflection. The process of applying optical coatings involves techniques like vacuum deposition and sputtering. These methods allow for precise control over the thickness and composition of the layers, ensuring optimal performance for various applications, including cameras, telescopes, and sunglasses.