Exercise 22: Eye and Vision
"Eye shine" in nocturnal mammals is different from the "red eye" seen in some flash photographs. Eye shine is the reflection of light off the tapetum lucidum. What visual mechanism might explain red eye?
Bright light reflecting off the back of the retina
What is astigmatism?
Defect in cornea or lens that causes an uneven bending of the light rays in that area of the eye
Because the lens is made of protein, what effect might the preserving fluid used in lab have on the same structure of the lens? How might this affect clarity?
Denature of proteins leads to refraction of light
What is the consensual reflex of the pupil?
Increase or decrease of one pupil when the other pupil is exposed to a respective decrease or increase in light.
How would you define the near point of the eye?
Minimum focusing distance of eye
In what area of the eye is the blind spot located?
Optic nerve
How does vitreous humor differ from aqueous humor in terms of location and viscosity?
Vitreous humor is located in the posterior cavity and is thicker
What numbers do 20/100 mean for visual acuity?
a person with this vision sees at 20ft what an average sighted person would see at 100ft
The iris of the eye has what function?
control the size of the pupil
What is the name of the transparent layer of the eye in front of the anterior chamber?
cornea
Which gland produces tears?
lacrimal gland
What is the function of the choroid?
nourishes the retina and absorption of light
Which nerve takes the impulse of sight to the brain?
optic nerve
Is the lens anterior or posterior to the iris?
posterior
What tunic of the eye converts visible light into nerve impulses?
retina
Which retinal cells are responsible for vision in dim light?
the rods
Where is the vitreous humor located?
vitreous chamber
What is another name for the sclera?
white of the eye
