lenses
what are the two types of lenses
double concave lens
double convex lens
what is same as shutter in the eye
eyelid
what is the function of the pupil and the iris?
pupil:the hole through which light enter
iris:controls the amount of light entering; the coloured part of the eye
which part of the eye carries a signal from the eye to the brain
optic nerve
in a refracting telescope what is the lens called that collects and focusses the light from a distant object?
objective lens
describe the thickness of each
double concave lens is thinner and flatter in the middle than around the edges
double convex lens is thicker in the middle than around the edges
what part of the camera is the same as the lens in an eye
lens
what is the function of the cornea?
protects the eyes
what is the natural adjustment of the pupils to changing light conditions called?
what is a lens?
iris reflex
a les is a curved piece of transparent material such as glass or plastic. light refracts as it passes through a lens causing it to bend
which of the following is NOT true about binoculars?
a. they are made of two refracting telescopes
b. they use convex lenses to focus the light and magnify the image
c. they use prisms that help transmit the light and make them shorter
d. they use a concave mirror to collect and focus the light
d
what happens to light rays in each lens (use the proper words)
concave lens - diverge, spread out
convex lens - converge, come together
what part of the eye is related to the protective glass
cornea
What is the function of the lens? and the eyelid?
eyelid - opens to take in light
what is the process called where the lens in your eye changes shape to adjust for different object distances
accommodation
tell me two things about reflecting telescope and refracting telescope and what do they have in common?
refracting telescope- light collected at objective lens, which is a convex lens
reflecting telescope- light collected at objective mirror or primary mirror which is a concave mirror
BOTH- have an eye piece lens, both lens and mirror act as a collector of light and both need to be big
what image is formed in each lens
convex - upside down/ inverted
concave - upright
what part of the eye is related to the aperture
pupil
what is the function of the retina?
captures the image, has light sensing cells and receives light and sends to the brain
is the blind spot in the SAME place in both eyes?
No, they are not in the same place
what is the function of an eyepiece lens in ALL the insrtuments we talked about?
the eyepiece lens magnifies and enlarges the image
what causes light rays to refract more in a convex lens
the curvature of the lens - convex lens with smaller causes it to refract more then a large curve convex
what part of the eye is related to the film, diaphragm, and focusing ring
retina, iris, ciliary muscles
what is the function of the ciliary muscle? and the humors?
adjust the lens for near or far away objects. controls the shape of the lens to ensure the image is focused on the retina.
the humors help the eyes to keep their shape and help to refract the light that enters the eye
using words and pictures explain the eyes of a nearsighted person, farsighted person,
- shape
- path of light
- type of lens needed to correct the vision
demonsrate it to class
what can you say about the amount of magnification in a reflecting telescope?
the father the image is from the lens the greater the magnification