Product description HOW TO PREVENT FOGGING? Activate the anti-fogging coating by soaking the inside lens before swimming. Never to use your fingers or towel to wipe off the inside of the lenses. Take a small drop of mild shampoo and gently rub it across the inner lens and rinse them. Use anti-fog spray. HOW TO PREVENT LEAKAGE? Make sure swim goggles sit on nose bridge and eyes comfortably and the sealing is perfect. Adjust strap and press the eye cups gently, make sure they fit tight to skin. Wear goggles beneath swim cap will keep them more firmly in place.