1)  good first impression of the lens on the patient since the power and fit are close to what they need to be.

2)  useful in cases when you do not have a trial lens close to what the patient needs as in toric GPs and keratoconus

What are the disadvantages of empirical fitting?

1)  you lose valable information on the lid/lens interaction

2)  movement of the lens

3)  topography variation since Ks only measure the central 2-3 mm of the lens

4)  you lose a warranty lens order since your first lens to order is the trial lens (usually you're allowed 2 exchanges in first 90 day period)

1)  bifocals

2)  irregular cornea (e.g. keratoconus, need to use corneal topography)

1)  best way to truly evaluate the on eye performance

2)  the first ordered lens will be more accurate

3)  can tweak parameters before buying a lens

1)  more chair time

2)  the first lens the patient tries is likely blurry and not extremly comfortable

1)  choose a fitting philosophy

2)  choose a lens diameter

3)  Choose a lens design

4)  choose a lens material

5)  choose a lens curvature

6)  choose a lens power

7)  evaluate the lens on the eye

8)  modify as needed

1)  studies show that the patient thinks the doctor is more knowledge

2)  Patient has more confidence in the doctor

3)  patient perceives more value in fit time and skills involved

1.  Lid contour

2.  Lid tension

3.  Topography

1.  lid attached

2.  interpalpebral a.k.a. intrapalpebral

1)  lid attached

2)  interpalpebral

1)  lid attached

2)  interpalpebral

3)  either

1)  the fitting philosophy you chose

2)  the corneal diameter

3)  the pupil size

1)  small diameter = 9.2mm

2)  large diameter = 9.6mm

3)  small diameter = 9.2mm

1)  Lid attached

2)  interpalpebral

1)  <3.00 D cyl.

2)  >2.00 D cyl

3)  sphere because its less expensive

1)  back toric or bitoric

2)  spherical

RA=Spec_cyl-corneal_cyl

0.75 D is maximum tolerable RA