Angular magnification is primarily provided by which category of optical devices?

Angular magnification is primarily provided by which category of optical devices?

• A. Handheld magnifiers
• B. Pinhole occluders
• C. Contact lenses
• D. TV screens

Answer: (A)

Angular magnification comes from devices that change how large an image appears to the eye by increasing its angular subtend. Handheld magnifiers use a convex lens held close to the object; this lets you bring the image into a position where it subtends a larger angle at the eye than the object does unaided, effectively making the object look bigger without moving your eye. The other options don’t provide true optical magnification: pinhole occluders don’t enlarge the image, they just limit light to increase depth of focus; contact lenses sit on the cornea and don’t create a larger angular image; TV screens can show a bigger picture, but that’s not optical magnification in the eye—it’s just a larger display viewed from a distance.

Angular magnification comes from devices that change how large an image appears to the eye by increasing its angular subtend. Handheld magnifiers use a convex lens held close to the object; this lets you bring the image into a position where it subtends a larger angle at the eye than the object does unaided, effectively making the object look bigger without moving your eye. The other options don’t provide true optical magnification: pinhole occluders don’t enlarge the image, they just limit light to increase depth of focus; contact lenses sit on the cornea and don’t create a larger angular image; TV screens can show a bigger picture, but that’s not optical magnification in the eye—it’s just a larger display viewed from a distance.