By the end of this chapter the student should be able to 

• understand the laws of reflection and refraction  
• learn the definitions like pole, centre of curvature, focus and focal length which are important in the study of spherical mirrors and lenses  
• draw the ray diagrams showing the image formation by spherical mirrors and lenses  
• know and use the sign conventions while using the lens and mirror formula  
• learn the definition and formula of magnification for lens and mirror.
• draw the ray diagram showing the refraction through a rectangular glass slab.
• learn about the power of lens.