Physical: Physical sunblock deflects solar energy through the use of minerals like zinc oxide and titanium dioxide. They do NOT react with your skin, which means they’re perfect for anyone with sensitive or reactive skin!
Physical sunblocks used to go on quite thick, leaving an opaque white layer on your skin. The latest sunscreens however don’t have any such superficial drawbacks, if applied correctly (dab evenly on: cheeks, chin, forehead, jawline. Press into skin as though you’re smoothing dough. Spread lotion to any part that is missing protection.) it absorbs completely!
Chemical: Chemical sunscreen works by absorbing the sun's solar energy and converting it through the means of a chemical reaction. Most times the result of this reaction is a quick conversion back to a sunscreen molecule, ready again to absorb rays, but SOMEtimes a byproduct of these reactions is a chemical that is in fact a carcinogenic. This does not occur regularily however, and the benefits of chemical sun protection are thought to outweigh the negatives. Something to consider for people with sensitive skin though, is that chemical sunscreen may cause photosensitivity and inflammation when exposed to the sun. In extreme cases this can even result in blistering of the skin.
Strength: In terms of strength, no "if"s "and"s or "but"s about it, you want to go with a broad spectrum sunscreen. This means that it includes both UVA (rays that cause aging) and UVB (rays that cause burning) protection. Our Cyberderm sunblock is 100% physical, provides broad spectrum protection, and includes additional hydrating ingredients (Cyberderm Simply Zinc also provides anti-aging benefits!).
In the summer, definitely try to keep your skin hydrated (through a hydrating facial like oh say our $99 July-August Hydralessence special) and/or hydrating home care products (Yonka's hydrating line is tax free for summer as well!). Of course drink lots of water, and wear your sunblock or sunscreen even on overcast days!