Specifically -
If the screen shows a closed lens or black image, force quit the Camera app.If you do not see the Camera app on the Home screen, try searching for it in Spotlight. If the camera does not show up in the search, check to make sure that Restrictions are not turned on by tappingSettings > General > Restrictions.Ensure the camera lens is clean and free from any obstructions. Use a microfiber polishing cloth to clean the lens.Cases can interfere with the camera and the flash. Try gently cleaning the lens with a clean dry cloth or removing the case if you see image or color-quality issues with photos.Try turning iPhone off on back .Find this on a different place give it a try & hope so help you out .