Definition of terms: Radio astronomy and radar systems often use dielectric
lenses, commonly called a lens antenna to refract
1. Myopia-nearsighted
electromagnetic radiation into a collector antenna.
2. Hyperopia-farsighted
3. Astigmatism- occurs when the cornea or lens is GUIDE QUESTIONS
curved more steeply in one direction than in another.
1. Consider a scenario where a person is diagnosed with
APPLICATION OF LENSES both myopia and astigmatism. How would an optometrist
design eyeglass lenses to address both refractive errors
A single convex lens mounted in a frame with a handle or
effectively, considering the non-axial symmetry of the
stand is a magnifying glass.
lenses?
Lenses are used as prosthetics for the correction of
2. Explore the interdisciplinary applications of lenses in
refractive errors such as myopia (used concave lens),
various imaging systems like cameras, microscopes, and
hyperopia (used convex lens), and astigmatism (used
projectors. How do the characteristics of lenses contribute
cylindrical lens). Sunglasses' lenses are designed to reduce
to the functionality of these devices?
the brightness of light; sunglass lenses that also correct
visual impairments can be custom made. 3. Investigate the historical use of lenses as burning
glasses for at least 2400 years. How did early civilizations
Other uses are in imaging systems such as monocular,
utilize this knowledge, and in what ways have
binoculars, telescopes, microscopes, cameras, and
advancements in lens technology expanded its applications
projectors. Some of these instruments produce a virtual
over time?
image when applied to the human eye; others produce a
real image that can be captured on photographic film or an 4. Did what you read help you understand the uses of
optical sensor or can be viewed on a screen. Concave lenses? How?
lenses are used in telescopes and binoculars to magnify
objects. As a convex lens creates blurs and distortion,
telescope and binocular manufacturers install concave
lenses before or in the eyepiece so that a person can focus
more clearly.
Convex lenses produce an image of an object at infinity at
their focus; if the sun is imaged, much of the visible and
infrared light incident on the lens is concentrated into the
small image. A large lens creates enough intensity to burn
a flammable object at the focal point. Since ignition can be
achieved even with a poorly made lens, lenses have been
used as burning glasses for at least 2400 years.
