Please, could you correct mistakes in my English text?

I wrote some text about optics and I am not sure if I make some mistakes in it. Can you help me, please? ;-)

I chose a textbook called Optics by Peatross and Ware published in 2004. We can see that the name of the textbook means the text is about optics and an electromagnetic field. From the textbook I chose four pages of the chapter 9 called Light and Rays. These four pages have two sections, the first section is Introduction and the second one is about The Eikonal Equation.
In the first section we can find information about the whole text of the chapter how the deadline reflects. The authors refer to problems and phenomena, which are solved in the chapter. They mention when we can use a ray theory. The ray theory is justification only for the macroscopic distribution of light when we can ignore diffraction phenomena and are not interested in changes of the electric intensity. The better theory is the wave theory that use wave feature of light. But it is more complicated then the ray theory we can use easily for describing imaging properties of optical systems like lenses or mirrors. The ray theory and the geometric optics are good tools for derivation of some basic optical laws such as the law of reflection and the law of refraction. These tools can be useful for people who have a geometric imagination and so they can imagine light by the ray theory. However no all-interesting phenomena of light can be described by the ray theory and we are made to use the wave theory. In the following sections of the chapture there are problems concern light as rays, for example the eikonal equation, Fermat’s principle, paraxial ray theory and others.
The second section I have read is about the eikonal equation. This equation describes the propagation of the ray in an optical medium. The propagation of the ray depends on the direction of the gradient of a wave front. The direction of the gradient means the direction normal to wave front surfaces.
I chose this text because I am interested in optics and wanted to study some branch of it. In my opinion the geometric optics (light as rays) is the easiest part of optics. It is easy to understand the problems using our imagination and intuition. The authors of the text write about problems clearly, understandably and sometimes they use some examples of phenomena in the nature. In the text we can find some pictures that are also important for studying and understanding. In the electromagnetic theory and optics Maxwell’s equations are very important and these evolutionary equations belong to the fundamental modern description of the nature. That’s why mostly equations or physical laws are derived from Maxwell’s equations. The eikonal equation is also derived from Maxwell’s equations because the authors begin the derivation of the eikonal equation with the wave equation that is naturally derived from Maxwell’s equations. Of course many laws and equations have been known before the Maxwell’s equations and so if we wanted the derivation of laws and equations to be in keeping with history of physics it wouldn’t be right to derive them from Maxwell’s equations. But I agree with the authors’ interpretation using Maxwell’s equations because it shows how the equations are general and fundamental for electromagnetic theory.

I did not major in English so double check anything I may tell you; I am curious about my own grammar ability. In the Sentence below there appears to be a mistake in agreement between the words, “ are problems concern”. Also, you misspelled the word chapter.

"In the following sections of the chapture there are problems concern light as rays, for example the eikonal equation, Fermat’s principle, paraxial ray theory and others."

I believe it would be correct if it was written as follows: In the following sections of the chapter there are problems concerning light as rays, for example the eikonal equation, Fermat’s principle, paraxial ray theory and others.



I hope I was some help, but double check.

:up: Thanks a lot, searcher! I'm pleased that you tried to correct my text.

I think its ok. NO grammar mistakes.:-D