There are soo many good swimming goggles out there at the minute! Speedo has an excellent thorough range to suit almost everyone. However My personal favourite is a pair of Zoggs predator flex. They have recently produced a reactor lens which is clear in dark environments and tinted in bright environments. They are on sale at the moment on amazon for around 30 reduced from 50. My standard pair for pool and open water swimming is the zoggs predator flex with clear lenses. The only time I have struggled with bright light/sun was at Bestfest in Majorca. Consequently I ended up breathing to the other side to get round this and changing to mirrored lenses for the remaining events. Incidentally I won a pair of Swedish goggles in May last year in a raffle and didnt particularly enjoy the fit around the eye socket. I know people that swear by them and I have seen many professional swimmers wear them but they are not for me.
In terms of swimming goggles for kids swimming lessons you wont go wrong with a pair of Speedo, Aqua Sphere, Maru or Arena. All top class excellent brands! I am a strong believer in you get what you pay for. If you purchase a pair of goggles for 3 dont be surprised if they steam up immediately, leak after a few swims and the strap breaks. A good pair should set you back 20-30, well worth the investment.