Eyes Flashcards
What does the iris do
Makes the pupil larger or smaller depending on the amount of light
Cornea
Focus light on the retina
The hole in the eye
Transparent part where light enters or let’s light through
Pupil
Lens
Part of of focusing process
Muscles around make it thicker or thinner depending on what your looking at
Retina
Where the image is formed.Has millions of light sensitive cones(rods and cones)
Sends the image to the brain(electronically)
Optic nerve
What is the blind spot and
When the image of the retina is also on top of the optic nerve.This point is soo dense with eye nerves that there is no room for light sensitive cells
Why do we see a white circle in between 2 black ones
Because are brain treats the black like night vision and is very sensitive.Are eyes look at the white and it is over sensitive and keep sending messages to our brain therefore we ‘see’ a white circle
Why can we sometimes see the word and not others
Because we look at the black we can’t see it
We look at white we can see the letters
Tag
Towards air glass
Aga
Air glass air
What happens when the ray enters the glass at 90
Travels straight through
What happens if the ray goes in at a different angle
It bends changes direction
What happens when a different angle comes out
Bends back to original angle
What is the connection between the ray entering and leaving
They are parllel
Refraction
When a wave moves through one medium to a different medium and changes speed
TAG =
slows down
Glass to air
Speeds up
Air to glass
Slows down
Light will not ——- when entêteront a different material at 90
Bend
What animal needs to understand refraction. To live
Archer fish
When rays pass through convex lens they
Converge
This converge is called a
Converging lens
What is the point where to the two lines meet called
Principal focus
When parallel rays pass through a line they
Diverge
This lens is known as a
Diverging lens
What two things happen when you look through a convex lens
Upside down
Back to front
Is an image through a convex lens clear
No blurry and confusing
Light from the top of eye focuses on
Bottom of retina
Light from bottom of image
Focuses on top of retina
What does the brain do to the image
Flip it
Converging
Cross lines
Diverging
Out wide lines
Light is a mixture of
Many different colours
The colours can be split into the
Spectrum
Using a what can light be split
A prism
Light refracts when entering a glass prism an spreads out In the colours of the spectrum when leaving this is called
Dispersion
What is the colour spectrum
Red. (Richard of York gave battle in vain)
Yellow
Orange
Green
Blue
Indigo
Violet
Real life example of dispersion
Rainbow
What is the electro magnetic spectrum
Sèvrerai types of radiation waves
Write the 7 types of radiation
Gamma rays
X-rays
UV rays
Visible rays
Infrared rays
Microwaves
Radio waves
Which type has longest wave length
Radio
What type is size of atom
Gamma
Relationship between wavelength and energy
Lower wave higher energy
Gamma
Sterilise fruit and veg and medical equipment
Can damage cells and cause camcer
X-ray
Bone X-rays,security at airport,X-ray metals for cracks
Damage cells and cause camcer
UV
Tan beds check bank notes sterilising
Cause cancer and damage cells
Visible light
Light bulbs,to screen,sun,photography
Overexposure can damage the retina
Infrared
Might vision goggles,fire heaters,toasters.Tv remotes
Burns skin
Microwave
Cooks food mobile phones satellites
Can heat tissue at specific frequency
Radio
Radio,some satellites
No dabger
Transverse wave
Vibration of particles are perpendicular to the direction of energy
Travels at
300,000,000m/s vacuum space
How do we see
Light Travel through the air
Iris control size, of pupil and amount of light let in
The light through the pupil
The light rays are bent(refracted)by the lens
Cornea bends(refracts) light rays is the enter the eye
The Image is focused on the retina which contains light receptor cells
The optic nerve carries the electrical impulse from the eye to the brain.
FAST
Faster away (the normal)
Slower towards
