If you’re helping someone else remove sunscreen from their eyes, reassure them with a soothing voice and move them to a well-lit spot, seating them in a position that gives you easy access to their face.
Alternatively, step into the shower. Then, with your face tilted toward the shower head, let a gentle stream of warm water flow from your forehead down into your held-open eye.
Use eye drops in addition to warm water to better flush your eye, restore moisture, and soothe irritation after the first rinse.
If your eyes still sting after a few hours, contact emergency services for help. If you’re helping someone else, have them tell you how they’re feeling every so often.
Also, keep your sunscreen on a high shelf or locked cabinet, where they’re unlikely to find and use it unsupervised.