A coated lens is a camera lens whose air-to-glass surfaces have been treated with a thin layer of magnesium fluoride or other anti-reflective coatings. These coatings reduce lens flare and ghosting caused by unwanted reflections, improving contrast, colour fidelity, and overall image quality. Coated lenses are especially beneficial in challenging lighting conditions, such as shooting against bright light or in outdoor photography, and are a standard feature in modern lenses used by both amateur and professional photographers.