Why does a convex lens fail to form a sharp image when used with white light unless corrected?
**Refractive index** n = c/v, water 1.33 means light 1.33 times slower than vacuum. Passing from water to air at 49°, n₁ sinθ₁ =1.33×sin49°≈1.33×0.755=1.004>1, so sinθ₂>1 impossible, total internal reflection occurs, no refraction. A convex lens exhibits chromatic aberration with white light because different wavelengths refract by varying amounts due to the lens’s material having a wavelength-dependent refractive index. This causes colored fringes as focal points differ for each color, blurring the image. Substituting values gives Due to chromatic aberration, which matches expected image posi
Ref: NCERT > Physics Book > Ray Optics > Refraction at Plane Surfaces and Snell's Law
