COT Flashcards : Contact Lenses 5%

Question 1

“A contact lens fit ““steeper than K”” is defined as a “

A. minus tear lens
B. corneal radius of 7.6 mm and the contact lens radius could be 8.8 mm
C. corneal measurement of 44.00 diopters and the contact lens curvature could be 44.50 diopters
D. base curve of the contact lens which is the same radius of the curvature of the anterior cornea

Answer 1

C. corneal measurement of 44.00 diopters and the contact lens curvature could be 44.50 diopters

Question 2

The DK value of contact lens material is the

A. measurement of the light transmittance of the material
B. measurement of the refractive index of the material
C. Oxygen transmissibility of the material
D. diffusion, solubility and movement of oxygen in the lens material

Answer 2

D. diffusion, solubility and movement of oxygen in the lens material

Question 3

All of the following are manifestations of hypoxia from a contact lens exept
A. giant papillary conjunctivitis
B. intraepithelial microcysts
C. stromal edema
D. warping of the cornea (irregular astigmatism)

Answer 3

A. giant papillary conjunctivitis

Question 4

Corneal astigmatism is BEST corrected by

A. extended wear spherical soft contact lenses
B. hydrogel spherical soft contact lenses
C. spherical RGP and soft lenses
D. spherical spin cast soft contact lenses

Answer 4

C. spherical RGP and soft lenses

Question 5

Lens warpage should be checked with a

A. lensometer
B. shadowgraph
C. slit lamp
D. radiuscope

Answer 5

D. radiuscope