Q: one dot not lit in macbook air green isight light

does anyone know what makes up the green isight light in 2012 macbook air?  I notice that one "dot" is not lit.  Not sure if I sure if it's worth taking to store to fix etc. although still under warranty.   Don't want them to open the screen for one tiny LED light. Is it many tiny bulbs or just one?  Would appreciate any info!