We encounter lenses and mirrors many times a day and are often oblivious to their form and function around us.
Many people even put lenses on their noses or directly on their eyeball to correct their vision.
One of the first things you do in the morning is probably look in a mirror. You may eat breakfast with a device that has two different types of mirrors on it. You drive to and from work or school looking behind you with the help of different types of mirrors. In a nutshell, life would be difficult without the many different optical devices we use throughout our life.