40 Questions
Where is the image of the object being viewed produced?
On the retina
What is the function of the cornea?
To focus by refracting light rays
What is the diameter of the pupil under normal light conditions?
4mm
What happens to the pupil's diameter in bright light?
It decreases to 3mm
What is the function of the iris?
To regulate the amount of light entering the eye
What is the function of the pupil?
To allow light to enter the lens
What is the primary function of the choroid in the eye?
To provide the blood supply for the retina
What is the purpose of the black pigment in the choroid?
To reduce the reflection of light within the eye
What is the result of blockage of the drain tube (canal of schlemm) in the eye?
Glaucoma
What percentage of the refractive power of the eye does the lens contribute to?
25%
What is the function of the ciliary muscles in the eye?
To change the shape of the lens
What is the role of the rods and cones in the retina?
To convert light energy into electrical energy
What is the primary characteristic of the Fovea?
It contains only cones.
What is the purpose of the accommodation process in the eye?
To ensure objects at various distances can be brought to a focus on the retina.
What is the main reason we do not notice the blind spot in our vision?
Because each eye compensates by seeing what the other doesn’t.
What is the main cause of farsightedness?
The lens is too weak.
What is the purpose of a converging eyeglass lens?
To correct farsightedness.
What is the main cause of astigmatism?
An irregular curvature of the cornea.
What is the main reason for the development of presbyopia?
Decrease in the flexibility of the lens
What is the term for the ability of the eye to see fine detail?
Visual acuity
What is the range of wavelength of visible light?
≈ 400 nm - 700 nm
What is the reason for the separation of white light into its constituent colors when passing through a prism?
Dispersion of light
What is the reason for an object appearing green in color?
All wavelengths except green are absorbed
What is the shape of the cornea that contributes to astigmatism?
Different curvature in different directions
What is the main function of rods in the retina?
To detect low light levels
How many types of cones are present in the retina?
3
What is the result of color blindness?
Absence of cones
What is the effect of color fatigue?
Reduced response to a color
Why is color matching important in dentistry?
To match the color of the dentine
How does the background color affect the appearance of an object?
It makes the object appear brighter
Rods are responsible for color vision.
False
There are only two types of cones in the retina.
False
Color fatigue is a result of absence of one or more types of cones.
False
Tooth enamel is opaque and does not allow light to pass through.
False
Dark backgrounds make materials appear darker.
False
Color matching is not important in dentistry.
False
Cones are highly sensitive and responsible for low light level vision.
False
Color blindness is a result of an absence of rods in the retina.
False
The perceived color is determined by the relative response of only one type of cone.
False
Prolonged exposure to one color has no effect on the eye's response to that color.
False
Learn about the structure and function of the human eye, including the cornea, pupil, and retina. Understand how the eye produces a real, inverted image of the object being viewed.
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