Being a pediatric ophthalmologist and neuro-ophthalmologist my self practicing since 11 years in Mumbai goregaon West, at latika eye and maternity specialty clinic ,dedicated to children's eye care , I have seen lot of surprises myself in this age group of 7 years as your child is in..so  very sorry no point in commenting about the numerous possibilities which your child might be facing. So it is better to get at least a basic eye check up and then discuss about it when the base line basic  examination findings are available. Best is to get your child examined by a pediatric ophthalmologist like me or at least get him examined by an ophthalmologist and least get the basic work up done .on those findings we can and love to guide you further. But without those basic  findings it is of no use to discuss further. For further info Pl visit www.latikaeyeandmaternityclinic.com Will be glad to help you . All the best.

On should not advise any medicine in 7 yrs old  child without physical examination but on safe side you may use antibiotic eye drops & lubricating eye drops(  genteal eye drops 4-5 times & Tobrex eye drops 4-5 times )at least for a week &if you don't get relief  you should consult local ophthalmologist, with regards

It might be allergy or viral conjinctivitis. Use lubricating eye drops 5 TIMES a day.