How does rain on the windscreen affect horizon perception?

• A. Horizon appears higher due to refraction
• B. Horizon appears lower due to water refraction
• C. Horizon perception unchanged
• D. Horizon disappears

Answer: (B)

Rain on the windshield creates a thin water layer that acts like a lens, bending light as it passes through before reaching your eyes. Because water has a higher refractive index than air, rays from the horizon are refracted in a way that shifts their apparent elevation downward in your field of view. The result is that the line where sky meets ground appears lower than it truly is. This effect doesn’t make the horizon disappear or appear higher; it simply alters the apparent position, often making the horizon look lower and distorting the view depending on droplet distribution and viewing angle.