I presume that you mean that the white parts of your son's eyes have changed to a brown colour. This is due to an eye allergy and is called ''vernal conjunctivitis''.Smoke and dust of any kind can aggravate this eye problem.From what you write here,the anti-allergic eye drops have not helped so far. It would be best to take your son to be seen by an eye specialist known as an ophthalmologist, Do not take him to an optometrist for this eye condition.
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