Ocean Salt Water and Pool Chlorine Damage to Glasses: How Saline Crystals & Corrosive Chemicals Attack AR

When ocean spray or salty sea mist hits your lenses, the water droplets evaporate rapidly under the sun and wind, leaving behind microscopic crystals of Sodium Chloride ($NaCl$):

$$\text{Salt Crystal Hardness: } Mohs\ 2.5 \quad \text{with razor-sharp cubic cleavage geometries}$$

If you take your shirt or dry towel and wipe the dried sea spray off your lenses, you are essentially grinding hundreds of razor-sharp mineral cubes into the delicate multi-coating. Within two wipes, you produce severe, irreversible scratch furrows.

Swimming pools are sanitized using chlorine gas, sodium hypochlorite, or calcium hypochlorite, forming Hypochlorous Acid ($HOCl$) in the water. Prolonged exposure to chlorinated water and pool vapors attacks the organic polymer bonding agents that anchor vacuum AR layers to the lens substrate, causing edge delamination and peeling.

1. NEVER wipe dry: If your glasses get splashed by sea water, resist every urge to wipe them with a towel, shirt, or dry cloth.
2. Submerge in fresh tap water immediately: Rinse the glasses thoroughly under fresh, cold tap water (or pour bottled mineral water over them) to dissolve the salt crystals completely.
3. Once all crystals are dissolved, wash with mild soap and pat dry with a clean microfiber cloth.