Later I heard that the price of an eye exam at target optical may vary from $29 to $229. So I think this may be the reason that why I can't find the price on the internet. if you want to have an eye exam at target optical, I strongly suggest you to make a call to know the exact price for en eye exam in that store.
Water does not commonly form a gas, but rather a vapor which is slightly different (but really just the name of a gas that is normally a liquid). - There is latent heat in water so you can remove energy without changing the temperature of the water (only exactly at a phase change though).
Clouds are also part of another important internal heat exchange process involving water phase changes. Most of Earth's free water is in the oceans (even more water is contained in the rocky crust of Earth), equivalent to a layer covering the whole surface about 2.5 km deep.