Refraction Quiz

Define and describe the physiologic characteristics of myopia, hyperopia, and astigmatism.

What are 3 things that a refraction is used for in clinic?

3) Define presbyopia

4) What is the Jackson Cross Cylinder used to determine?

5) Name at least 3 methods of correcting refractive errors of the eye.

6) How many diopters of change would you expect to give to a healthy patient who has a distance visual acuity of 20/30 but pinholes to 20/20?

7) Define and state the purpose of an add in a multifocal lens.

8) Name the kind of ophthalmic lens used to correct the following refractive errors: myopia, hyperopia, and astigmatism.

9) Distinguish between cycloplegic refraction and manifest refraction.

10) Name the 3 components of the lens prescription: +2.75 +1.50 x135

11) Transpose the following lens prescriptions: +4.25 +1.50 x135 -3.00 +1.00 x 85 -2.50 -3.00 x 010

12) Name the type of lens identified by lensometry when the single and triple perpendicular lines come into focus simultaneously.

13) True or false: Plus lenses magnify objects while minus lenses minify objects.

14) True or false: A 15 year-old girl’s lens has about 3 diopters more accommodative ability than a 5 year-old girl’s lens.

15) For an established patient wearing 2 year old glasses, the most efficient starting point for today’s refraction is the:

16) A patient with too much plus correction in their bifocal will have to hold reading materials closer or farther away? Why?

17) You are performing a refraction on this 45 year-old patient. What would you expect his complaint to be regarding his vision with his spectacles on? Distance vision with correction: OD 20/20 OS 20/20 Present Rx: OD -1.50 sph, no add OS -1.50 sph, no add

18) You are doing refraction on a 41 year-old pseudophakic patient (S/P Phaco w/ IOL). Which of the following adds would you give for the manifest refraction?

19) Giving a young patient a few too many clicks of minus during a refraction can cause:

20) A 51 year old patient has a +2.25 add in their current glasses and has no complaints at today’s visit. The patient’s near visual acuity has not changed since their last visit. Which add would you give them for today’s manifest refraction?

21) A 35 year old established patient presents with a complaint of blurry vision at distance. The patient states that for his new occupation he started a few years ago, he spends 60+ hours in front of a computer per week. The patient’s distance acuities are 20/60 in the right eye and 20/40 in the left eye with present correction. Near acuities are J1+ in both eyes. The patient pinholes to 20/20 in each eye. Which of the following manifest refractions makes the most sense and is most likely to bring the patient to 20/20? Lensometry OD: -4.00 +0.75 x165 OS: -4.50 +1.00 x020 Autorefraction OD: -3.50 +1.75 x180 OS: -3.75 +1.25 x005 Keratometry (K’s) OD: 45.00/46.25 x 174 OS: +44.75/46.25 x 180

22) A 50 year-old patient is new to GRO, and complains of distorted vision. The patient’s distance acuities are 20/50 in each eye with the present correction. The patient pinholes to 20/20 in each eye. The patients’ near acuities are J10 in each eye, with the present correction. Which of the following manifest refractions would make the most sense and is most likely to bring the patient’s distance acuity to 20/20 in each eye? Lensometry (7 years old) OD: -6.00 +0.25 x90, +1.50 OS: -7.50 +0.25 x90, +1.50 Autorefraction OD: -6.25 +2.75 x030 OS: -8.25 +3.00 x158 Keratometry (K’s) OD: 44.75/ +47.25 x034 OS: 44.50/+47.50 x155

23) What is “neutralization”?

24) A 75 year –old established patient had cataract surgery (S/P Phaco w/ IOL w/ Toric) 43 days ago in the right eye and needs a post op refract. The left eye is not ready for surgery yet. The patient’s acuities are 20/30 in the right eye without correction and 20/20 in the left eye with correction. The patient pinholes to 20/20 in the right eye. Which of the following manifests makes the most sense and is most likely to bring the patient’s acuity to 20/20 in each eye? Lensometry (1 year old) OD: +0.75 + 3.50 x24, +2.50 OS: +1.00 +4.00 x168, +2.50 Autorefraction OD: -0.25 +1.00 x030 OS: +0.50 +4.75 x170 Keratometry (K’s) OD: 42.50/45.00 x026 OS: +42.00/46.75 x171