Geometrical Optics and Image Formation (4D) Practice Test

A surgical headlamp uses a converging lens to collimate light from an LED so the illuminated field is uniform at working distance. The LED is positioned on the optical axis at a distance equal to the lens focal length. The design team checks the beam by placing a screen several meters away. Using the thin-lens equation as the central concept, which outcome is most consistent with this setup?

A contact lens is tested on an eye model. Without correction, the model’s eye lens focuses parallel rays to a point $2,\text{mm}$ in front of the retina (myopia). A diverging contact lens is placed directly on the cornea to shift the focus onto the retina for distant objects. Using only qualitative ray reasoning (single central concept: diverging lens effect on parallel rays), which prediction is most likely accurate?