What is a reason for heating cockpit windows?

Heating cockpit windows serves primarily the function of anti-icing. This process ensures that ice does not form on the glass surfaces, which could obstruct the pilots' view and impair their ability to operate the aircraft safely. By preventing ice buildup during flight, the anti-icing system helps maintain clear visibility and supports the aircraft's aerodynamic performance.

Other aspects like deicing pertain to the removal of existing ice, while preventing thermal shock focuses on protecting materials from rapid temperature changes. Improving visibility is a secondary benefit that can result from maintaining clear windows through heating, but the primary purpose is to prevent ice formation, making anti-icing the correct reason for heating cockpit windows.