Quiz 2 Info Flashcards
If you increase the thickness of the crystalline lens, what happens to the dioptric power?
It decreases
If you increase the thickness of the corneas, what happens to the dioptric power?
It increases
Where is the entrance pupil found?
In air
Where is the exit pupil found?
In the vitreous
What structure do the photoreceptors turn toward?
The center of the pupil
What optical property to photoreceptors use to catch light?
Total internal reflection
What is depth of field/focus?
The range of an object or image plane over which the image appears to be in focus
Where are light-scattering nuclei of the lens found?
Near the equator
Close packing of cells reduces light scatter of the lens where?
At cell boundaries
Why doesn’t the lens absorb much light?
No pigments and avascular
How does the crystalline lens refract light?
It varies the thickness and refractive index
What is the accommodated power of the lens?
31.85D
What is Helmholtz’s theory?
That a decrease in tension of all the zonules increases optical power.
An increase in mass and stiffness of the lens with age reduced lens deformation
What is Schachar’s theory?
Increased tension in equatorial zonules and decreased tension in the anterior and posterior zonules increase optical power.
Decrease in space between ciliary muscle and lens causes the zonules to become slack
What law governs light rays that form images on the retina?
Snell’s law
