# Hotel Peephole Lens: Achieving a 180-Degree View Through Refraction

Chapter 23, Problem 93

(choose chapter or problem)

QUESTION:

How can the peephole lens in a hotel door have an approximately $$180^\circ$$ view?

(a) The light moves straight through the lens into the eye.

(b) Light from about $$90^\circ$$ from the straight-ahead direction is refracted into the observer’s eye if very close to the lens.

(c) Light from about $$90^\circ$$ from the straight-ahead direction is refracted into the observer’s eye if looking at the lens from inside the room.

(d) The outside hall is illuminated so reflected light from the objects inside the $$180^\circ$$ angle goes into the lens.

(e) Both b and d.

QUESTION:

How can the peephole lens in a hotel door have an approximately $$180^\circ$$ view?

(a) The light moves straight through the lens into the eye.

(b) Light from about $$90^\circ$$ from the straight-ahead direction is refracted into the observer’s eye if very close to the lens.

(c) Light from about $$90^\circ$$ from the straight-ahead direction is refracted into the observer’s eye if looking at the lens from inside the room.

(d) The outside hall is illuminated so reflected light from the objects inside the $$180^\circ$$ angle goes into the lens.

(e) Both b and d.

Step 1 of 3

Refraction is the phenomenon that involves the bending of light as it passes from one transparent medium to another. This phenomenon also occurs with sound, water, and other types of waves. It is because of this refraction or bending that we can make use of lenses, magnifying glasses, prisms, and even observe rainbows.

##### Hotel Peephole Lens: Achieving a 180-Degree View Through Refraction

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Uncover the fascinating science behind peephole lenses, including the principles of light refraction and observer positioning that allow for an extensive field of vision through a hotel room door.