FITTING SOFT TORIC CL

Question 1

Factors in fitting soft toric CL

Answer 1

● Astigmatism
● Eyelids
● Lens design
● Lens selection
● Fit Assessment

Question 2

The____________ and _________are important factors when fitting patients with soft toric lenses.

Answer 2

magnitude; axis of astigmatism

Question 3

It has been said that it is acceptable to fit spherical soft lenses when a patient’s

Answer 3

cylinder power is less than 25% of the spherical power

Question 4

1. ____________ astigmats may be better candidates than those who have 2._____________ or 3._____________ astigmatism because of the geometry of lens design

Answer 4

1. ATR
2. WTR
3. Oblique

Question 5

plays a critical role in contact lens rotational position and stability

Answer 5

eyelids

Question 6

Tight lids exert greater force and___________

Answer 6

torque

Question 7

Smaller______________________ are associated with increased rotational stability

Answer 7

palpebral apertures

Question 8

if inner canthus is higher lens tend to rotate

Answer 8

nasally

Question 9

if outer canthus is higher lens tend to rotate

Answer 9

temporally

Question 10

When selecting a soft toric lens brand, consider the following:

Answer 10

1. corneal curvature
2. corneal diameter
3. corneal toricity
4. refractive error
5. eyelid architecture

Question 11

corneal diameter

Answer 11

HVID

Question 12

this may play a role soft toric lens selection especially in patients with tight lid tension and narrow palpebral fissure

Answer 12

eyelid architecture

Question 13

T/F
The goal of spectacle is to meet the physical & physiologic requirements of the eye, & to address the visual requirements of the eye

Answer 13

F

The goal of contact lens is to meet the physical & physiologic requirements of the eye, & to address the visual requirements of the eye

Question 14

a major component that contributes to the patient total astigmatism.

Answer 14

corneal toricity

Question 15

it is the amount of astigmatic refractive error that remains uncorrected when a contact lens (spheric; toric; soft or rigid) is applied to the cornea to correct the refractive error

Answer 15

residual astigmatism

Question 16

The residual astigmatism of a spherical soft lens is the same as the _________________

Answer 16

refractive astigmatism

Question 17

Physiologic residual astigmatism arise from

Answer 17

a. Contributed power from the different meridians of the crystalline lens

b. Contributed power from the posterior cornea-aqueous interface

c. Variations in refractive index of the cornea, lens

d. Obliquity of light incidence to the cornea

e. Eccentricity or irregularity of the fovea

Question 18

it is the amount of astigmatism which is contributed by the presence of the lens on the eye because of:
○ lens flexure (i.e. fold)
○ decentration
○ warpage (i.e. is a distortion where the
surfaces of the molded part do not follow the intended shape of the design)
○ tilt of CL

Answer 18

induced residual astigmatism

Question 19

Induced residual astigmatism is the amount of
astigmatism which is contributed by the presence of the lens on the eye because of:

Answer 19

○ lens flexure
○ decentration
○ warpage
○ tilt of CL

Question 20

a distortion where the surfaces of the molded part do not follow the intended shape of the design

Answer 20

warpage

Question 21

how can residual astigmatism affect the visual performance of the contact lens?

Answer 21

1. reduction of the visual acuity
2. exhibiting asthenopia