When you don't know what to write about... Write about geometrical optics)) 'What would I write about?' I thought. 'Write about geometrical optics' said my husband. Well, what can I write about it in a few words? Geometrical optics is the one of two divisions of optics that studies light as a collection of rays. The rays travel in straight lines and can refract or reflect from surface. So, if you study geometrical optics you have to know Law of Reflection and Law of Refraction (Snell's Law). Studying basic optics you also will learn how to illustrate image formation by lenses (thin or thick, positive and negative) and mirrors (plane and spherical). I think, geometrical optics is not so difficult as physical (wave) optics. So, if you interested in physics generally and optics particularly you can discover a wonderful world for you! Good luck! And you have an advantage because there are a lot of prime information resources in your language (English)!!