A wet camera lens is susceptible to mold and other issues.
Water is no friend to a camera lens, especially newer models that use electronics to send lighting and focus information to the camera body. A few raindrops won't cause serious damage, but if your lens gets significantly wet or even submerged in water, you'll need to act quickly to prevent permanent damage. It will take several days of drying out before you will know how much damage the water has done to your lens.
Instructions
1. Remove the lens from the camera. Remove any filters from the lens.
2. Shake out any water from inside the lens.
3. Gently wipe the outside of the lens down thoroughly with a towel.
4. Place the lens and a small amount of silica gel or other drying agent (like the small pouches of compound manufacturers use when packing products from shoes to electronics) inside the bag. Let it sit for at least a day while the compound absorbs the moisture. You can even try using rice.
5. Allow the lens to continue to dry out for several days.
6. Apply a drop or two of lens cleaning solution to the glass and wipe with a soft cloth to remove any water spots left behind.
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