Chapter 11 - Lenses and The Eye Flashcards
What does a converging/convex lens do to light?
Focuses parallel light rays to the principal focus
What does a diverging/concave lens do to light
Spreads parallel light rays out as if they had just come from the principal focus
When does a converging/convex lens form a real image?
When the object is further away than the principal focus
What image is formed by a diverging/concave lens?
Virtual
When does a coverging/convex lens form a virtual image?
When the object is nearer to the lens than the principal focus
When would you use a ray diagram?
To find the position and nature of he image formed via a lens
Describe the image formed when the object is placed between the converging/convex lens and its principal focus
Virtual, upright, magnified and on the same side of the lens as the object
What type of lens does a camera use?
Converging/convex
What type of lens does a magnifying glass use?
Converging/convex
What values do real images and converging/convex lenses have?
Positive values
What values do virtual images and diverging/concave lenses have?
Negative values
Where is light focused to on the eye via what?
Retina via cornea and eye lens
What muscles change the shape of the eye lens?
Ciliary muscles
What is the range of vision of the human eye?
25cm-infinite
What type of lens does a camera and eye have?
Converging/convex
What type of focusing adjustment do the camera and the eye have?
Adjustment of the lens position, and ciliary muscles alters lens thickness
What type of image do the eye and camera form?
Real, inverted, magnification less than 1
What type of image detection do the camera and eye have?
Photographic film or CCD sensors, light sensitive cells in the retina
What type of brightness control do the camera and the eye have?
Adjustment of the aperture, iris controls width of they eye pupil
How can you correct short-sightedness?
Diverging/concave lens
How can you correct long-sightedness?
Converging/convex lens
How can you make the lens material thinner and flatter?
By increasing the refractive index
Where does the image form in short-sightedness?
Short of the retina
Where does the image form in long-sightedness?
Long of the retina
