Aside from the green lens, avoid wearing leather or mail as much as possible. Armor is key to how well teh class/spec does. You have to sit and take alot more damage because you have to sit still to cast any heals. I cant help but laugh at the retard pallies wearing cloth, we can take them down so much easier, the bit of extra +heal they get doesnt even come close to make up for all the extra damage they take. Which means they have to heal themselves more and others less, and they die more, which means less healing too. Its just not good to sacrifice armor, you can do it for a piece of gear or two tops, but thats it.
Also, mp5 on chants or gear is junk, ignore it, your mana lasts 3x longer than a priests anyway, you dont need it. This also means you dont need to stack a bunch of int. 26-2800 is all i have, and spamming heals non stop, i very very rarely go oom. Compare it to my priest who has 3800 and spends half the fights oom constantly.
With the Flash of light glyph, weapon oil and gear you should average around 480-500 per non-crit flash. And that will be with all mail armor except the green lens. Compare that to sub 200 base flash and you see that a 250% effect flash is quite efficient and very effective.
On a side note, if you find yourself fighting alot of rogues/fury warriors/feral druids, then try out a green whelp armor. You lose a decent amount of stamina tho and intellect and armor, however it procs like mad vs those classes and will protect you from far more damage than you lose stamina/armor wise and the mana loss is no biggie as you really have no mana issues. I switch between it and my eagle chest depending on what im gettin hit by.
You can armory Nakiera of argent dawn to see my gear. You could get the boa shoulders for healing (i use the dps ones from my ret pally for the huge stam bonus, til next patch anyway), and the new buffed boa healing mace will be the best next patch too, but otherwise most of the gear is what you will want to use.