The world needs science, and science needs women. Today, we celebrate the 10th anniversary of the International Day of Women and Girls in Science, which highlights the urgent need to close the gender gap and foster inclusive environments where women and girls can thrive in the sciences. Women in optics provide words of advice for the next generation of scientists: "Have confidence in yourself and don't be afraid to take action." 1997 Optica President Janet Fender "Consider exploring all potential opportunities at each stage of your career and select the optimal environments and colleagues for collaboration." Optica Fellow Ursula Keller "Decisions you make now do not have to determine the rest of your life. Changing your mind is OK and gives you an opportunity to learn." Optica Ambassador Gabrielle Thomas "Hang in there – things may get difficult sometimes, but hard work and perseverance will guide you." Tammy Ma, Lead for the Inertial Fusion Energy Institutional Initiative at Law...