Does too much UV light exposure make a green iguana more violent?

No, they need UV or they will die. Why would it get violent?

No, but I think I know where you might have heard of this. Iguana owners sometimes noticed that after getting their iguana real sunlight, they would get more aggressive, but this was from the stress of being introduced to the noisy outside world, not the light. One thing that an increase of UV light will cause is the iguana's skin to stay dark for a few days. This shouldn't affect their behavior, it's only their skin protecting itself.

A real excess of UV light would cause eye problems, but it won't happen with a reptile lamp or the sun. It could happen if you used a tanning lamp, but few people are dumb enough to do that.

If he is not shedding all over at once he is not healthy. Iguanas need UV light 12 hours a day. You need to purchase one. Sunlight is the best, and always helps, but who has the time to sit outside with your iggy 4 hours a day? Iggy should be light green, when their skin tone darkens it is a sign of illness. He should be eating fresh veggies and dark leafy green (NO lettuce) dusted with calcium/phosphours avail at your pet store, every day. I am also an iguana owner. He has lightened up because he is healthier and digesting better because of the UV light (sunlight). Iggys need UV because they senthasize it into vitamin D, we naturally produce it but we are not reptiles. Iggys must have this sunlight manufactured vitamin D in order to use calcium so their bones will grow. Without it they develop MBD (metabolic bone disease) and their bones become like speghetti and will begin to break. A mush jaw or broken bones (or missing toes/nail) is a early indicator of MBD.

No no no !!! They need UV light. And even though you provide them with UV Bulb, consider getting them in the sun for NATURAL UV at least once a week for 30min. UV helps with their growth, bone structure, digestive process etc. UV is VERY important as well as humidity. Remember they are actually tropical animals...

no UV exposure may make them more active but this is a good thing