• Tags: apparent-depth, refraction, plane-surface
• Difficulty: Foundation

When viewing an object in a denser medium from a rarer medium: apparent depth = real depth / n.

For multiple slabs: apparent depth = $t_{1}$/$n_{1}$ + $t_{2}$/$n_{2}$ + ... (each slab contributes independently).

Lateral shift through a glass slab: d = t × sin$\frac{i-r}{cos}$(r), where t is slab thickness, i is angle of incidence, r is angle of refraction.

Normal shift (object viewed through slab): $\Delta$ = t(1 - 1/n). The object appears shifted by this amount toward the observer.