You may feel like you need a map to navigate the sunscreen aisle at your local pharmacy.

To help sort through which sunscreens really are best, we went shopping with a dermatologist.

First thing's first, you need to know there's a difference between sunscreen and sun block.

UVB rays are the ones that cause burns. UVA rays tend to age the skin. Both can cause cancer.

Also be careful to look for water proof not water resistant.

And when it comes to sun protection factor or SPF, higher numbers don't always translate as you'd expect.

And be aware, no SPF is powerful enough to let you lay on the beach all day protected.

For kids the rule is no sunscreen for infants six months or younger, after that you have free rein.

As for new ingredients, you may notice things like Helioplex on the label.

And remember this, more expensive doesn't always mean better.