Ametropia Flashcards
The anterior focal point is 15mm in front of the principal plane of a refractive ametrope’s eye. What is the patient’s ocular refractive error?
a. Hyperope, 6.67D
b. Hyperope, 7.78D
c. Myope, 4.86D
d. Myope, 6.67D
e. Myope, 7.78D
Myope, 6.67D
The far point of an axial ametrope is located 15cm in front of the eye’s principal plane. Assume that the spectacle plane is 15mm in front of the eye’s principal plane. What would be power of the spectacle lens required to correct the eye for infinity?
a. –6.67D
b. +6.06D
c. –6.06D
d. –8.53D
e. –7.41D
e. –7.41D
What would be the distance between the principal plane and retina for a 9D axial myope?
a. 26.14mm
b. 22.22mm
c. 19.32mm
d. 25.55mm
e. 28.01mm
a. 26.14mm
What would be the distance between the principal plane and retina for a 9D axial hyperope?
a. 26.14mm
b. 22.22mm
c. 19.32mm
d. 25.55mm
e. 28.01mm
c. 19.32mm
Which of the following changes in isolation would cause an emmetropic eye to become myopic?
a. an increase in the refractive index of the vitreous
b. a decrease in the depth of the anterior chamber
c. an increase in the radius of curvature of the anterior corneal surface
d. a decrease in the refractive index of the aqueous humor
e. an increase in the refractive index of the cornea.
a decrease in the depth of the anterior chamber
For an axial ametrope, the distance between the nodal point and the retina is 24mm. What is the eye’s ocular refractive correction (CL Rx)?
a. –14.88D
b. –8.88D
c. –4.44D
d. –12.27D
e. +12.27D
a. –14.88D
The anterior (primary) focal length of a refractive ametropic eye is –14mm. What is the eye’s ocular refractive correction (CL Rx)?
a. –35.23 D
b. –11.43 D
c. –22.68 D
d. –7.39 D
e. –9.77 D
b. –11.43 D
The secondary focal length of a refractive ametrope is 21 mm. What is the eye’s ocular refractive error?
a. +6.34 D
b. +12.38 D
c. +3.49 D
d. +2.59 D
e. +1.98 D
c. +3.49 D
A myopic patient has a +5D ocular refractive error. Where does a –10D lens have to be placed to create the proper distance correction? Assume that the patient does not accommodate.
a. 20 mm in front of the eye’s principal plane
b. 40 mm in front of the eye’s principal plane
c. 60 mm in front of the eye’s principal plane
d. 80 mm in front of the eye’s principal plane
e. 100 mm in front of the eye’s principal plane
e. 100 mm in front of the eye’s principal plane
The eye’s near point is _________________
a. the point conjugate to the retina when the eye is uncorrected but fully accommodated.
b. the point conjugate to the retina when the eye is corrected for distance and fully accommodated.
c. always located between optical infinity and the eye’s principal plane.
d. always physically closer to the eye’s principal plane than the eye’s far point.
a. the point conjugate to the retina when the eye is uncorrected but fully accommodated.
You are performing distance Retinoscopy at a working distance of 50cm. No working lenses are in place, +2.50 neutralizes the 180 meridian and +3.75 neutralizes the 90 meridian, what is Rx? a. +0.50 + 1.25 x 180 b. +1.75 -1.25 x 90 c +1.75 -1.25 x 180 d. +3.75 -2.50 x 180 e. +3.75 -2.50 x 90
b. +1.75 -1.25 x 90
You are performing distance Retinoscopy with no lenses in place. The streak is vertical and neutralized motion is seen at a distance of 50cm. Then the streak is held horizontally and neutralized motion is seen at a distance 25cm. What is the Rx? a. -2.00 - 2.00 x 180 b. +2.00 -2.00 x 090 c Plano -4.00 x 180 d. Plano -4.00 x 090 e. -2.00 + 2.00 x 90
a. -2.00 - 2.00 x 180
You are performing near retinoscopy and the patient is looking at your scope 40cm away. You use +0.75 to neutralize the motion. How much is the patient accommodating?
a. 2.50D b. 3.00D c. 1.75D d. 1.00D e. 1.50D
c. 1.75D
The farthest away (FP) a patient can see without accommodation is 50cm while wearing a -1.00 lens. What is their refractive error?
a. 2.00D Myope b. 3.00D Myope c. 1.00D Hyperope d. 1.00D Myope e. 2.00D Hyperope
b. 3.00D Myope
The nearest point (NP) an emmetropic patient can see with full accommodation through a -2.00 lens is 20cm. What is their accommodation?
a. 0.00D b. 1.00D c. 3.00D d. 5.00D e. 7.00D
e. 7.00D