PMS - Special Senses (vision) Exam
1. What separates the anterior and posterior cavity?: - lens
2. What separates the anterior and posterior chambers?: - iris
3. What is refractive index?: - the ratio of the speed of light in air to its speed in a substance
4. What is the concept of refraction at interfaces?: - light rays bend through an angulated
interface between two media with different refractive indices
- light rays entering a perpendicular interface DO NOT DEVIATE
5. How do concave lenses refract light?: - diverge parallel light rays
6. How do convex lenses refract light?: - converge parallel light rays to a focal point
7. How do cylindrical lenses refract light?: - bend light rays to uniformly focus parallel rays to a focal
line
8. What is focal length?: - distance beyond a convex lens where parallel rays converge at a focal point
1/8
,9. What is refractive power measured in?: - diopters (1/focal length in meters)
10. What kind of diopters do convex and concave lenses have?: Convex lenses have
positive diopters
Concave lenses have negative diopters
11. What are the four refractive interfaces of the eye?: - air/cornea
- cornea/aqueous humor
- aqueous humor/lens
- lens/vitreous humor
12. What is the reduced eye model?: - simplified model considering all refractive surfaces as a single
lens
13. How is refractive power divided between the cornea and lens?: The anterior surface
of the cornea provides about 2/3 of the eye's total refractive power
The internal lens contributes about 20 diopters and is crucial for ACCOMMODATION
14. Describe the process of imagine formation on the retina?: - the eye's lens system
focuses an inverted and reversed image onto the retina and the brain perceives this image as upright
2/8
, 15. What is emmetropia?: normal vision
- parallel light rays focus sharply on the retina when the ciliary muscle is relaxed
16. What is myopia?: nearsightedness
- light focuses in front of the retina, usually due to a long eyeball or strong lens system
3/8
1. What separates the anterior and posterior cavity?: - lens
2. What separates the anterior and posterior chambers?: - iris
3. What is refractive index?: - the ratio of the speed of light in air to its speed in a substance
4. What is the concept of refraction at interfaces?: - light rays bend through an angulated
interface between two media with different refractive indices
- light rays entering a perpendicular interface DO NOT DEVIATE
5. How do concave lenses refract light?: - diverge parallel light rays
6. How do convex lenses refract light?: - converge parallel light rays to a focal point
7. How do cylindrical lenses refract light?: - bend light rays to uniformly focus parallel rays to a focal
line
8. What is focal length?: - distance beyond a convex lens where parallel rays converge at a focal point
1/8
,9. What is refractive power measured in?: - diopters (1/focal length in meters)
10. What kind of diopters do convex and concave lenses have?: Convex lenses have
positive diopters
Concave lenses have negative diopters
11. What are the four refractive interfaces of the eye?: - air/cornea
- cornea/aqueous humor
- aqueous humor/lens
- lens/vitreous humor
12. What is the reduced eye model?: - simplified model considering all refractive surfaces as a single
lens
13. How is refractive power divided between the cornea and lens?: The anterior surface
of the cornea provides about 2/3 of the eye's total refractive power
The internal lens contributes about 20 diopters and is crucial for ACCOMMODATION
14. Describe the process of imagine formation on the retina?: - the eye's lens system
focuses an inverted and reversed image onto the retina and the brain perceives this image as upright
2/8
, 15. What is emmetropia?: normal vision
- parallel light rays focus sharply on the retina when the ciliary muscle is relaxed
16. What is myopia?: nearsightedness
- light focuses in front of the retina, usually due to a long eyeball or strong lens system
3/8
