C: Light and Optical Systems, section 4: eyes and cameras Flashcards
What is the function of the cornea?
Protect all the sensitive parts of the eye
What is the function of the iris?
To control the size of the pupil
What is the function of the pupil?
To let in more or less light
What is the function of the ciliary muscle?
To make the lens thicker or thinner
What is the function of the lens?
To focus the light onto the retina
What is the purpose of the retina?
To send the image to the optic nerve
What is the function of the optic nerve?
To send the image to the brain
What does it mean when the pupil dilates?
Becomes bigger
Which part of the camera is like the retina?
The film
What part of the camera is like the iris?
The diaphragm
What part of the camera is like the eyelid?
The shutter
What part of the camera is like the lens?
The lens!
What part of the camera is like the pupil?
The aperture
What is the retina?
It is the sensitive layer that like strikes. It is filled with photo receptors
What are rods sensitive to?
Light
What are cones sensitive to?
Color
Why can’t you see colors in the dark?
Because comes don’t work very well in low light
What happen when light strikes the retina?
The photoreceptors send light to the optic nerve
What is farsightedness?
When the light doesn’t focus early enough
What is nearsightedness?
When the light focuses to early
How is farsightedness corrected?
It is fixed with convex lenses
How is nearsightedness corrected?
It is fixed with concave lenses
How does laser eye surgery work?
The surgeon uses a laser to reshape the cornea
How do night vision goggles work?
Light goes through light intensifiers and then through a phosphor screen which causes them to glow green
What are the parts of the eye?
Cornea Iris Pupil Lens Ciliary muscle Retina Optic nerve
What are camera eyes?
Any eye that has a cornea, lens, and a retina
How many comes do humans have?
3: each different ones sense red, green, blue
How many different cones do birds have?
5
What is tapetum lucidum?
It’s basically a mirror inside the eye that reflects light outside of the eye
What organisms have compound eyes?
Insects and crustaceans
What is a compound eye?
Eyes that are made of many ommatidium
What does an ommatidium look like?
A long tube with a lens on the outer surface
What are advantages to compound eyes?
You can see in all directions
You can see motion very well
What are downsides to compound eyes?
Can’t form a single image
What are camera eyes?
Any eye that has a cornea, lens, and a retina
How many comes do humans have?
3: each different ones sense red, green, blue
How many different cones do birds have?
5
What is tapetum lucidum?
It’s basically a mirror inside the eye that reflects light outside of the eye
What organisms have compound eyes?
Insects and crustaceans
What is a compound eye?
Eyes that are made of many ommatidium
What does an ommatidium look like?
A long tube with a lens on the outer surface
What are advantages to compound eyes?
You can see in all directions
You can see motion very well
What are downsides to compound eyes?
Can’t form a single image
What is digital imaging?
The process of creating a big picture out of small images
What happens when a computer receives an image?
It divides them into pixels and then changes it to numbers
What does a computer do to tell color?
It assigns the color a number
What is the resolution?
It refers to the number of pixels per unit area
What is the difference between cameras and digital cameras?
Instead of light falling on agile it falls onto a charge-coupled device or CCD
How does a charge coupled device work?
As light falls into each square it creates a small amount of electricity. It’s then created into digital information like numbers
