GP and Soft Multifocal (M1) Flashcards
What are the different types of segmented MF lenses?
- fused designs (diff indices of refraction)
- one piece designs (diff anterior surface curvatures for dist and near zones with ledge)
- intermediate zones (look like trifocals)
For the Blanchard Essential lenses, what does changing the series of the lens affect?
- position
- movement
- stability
- fluoroscene
What are the different aspheric back surfaces on a multi-aspheric GP for?
- central aspheric curve provides dist and add
2. peripheral aspheric curve fits peripheral cornea
If a GP lens is riding temporally, what should be done?
- increase lens diameter by 0.5 or 0.3mm
2. specify minus carrier
What should be done to Modified Monovision lenses with distance complaints?
- Decrease add in distance eye
- Eliminate add in distance eye (SV)
- increase minus in distance eye
If poor near vision is occurring in a translating design, what should be done?
- raise seg height
- improve translation
- increase add power
What are the lens types for concentric multifocals?
either center-distance or center-near
What do the single aspheric GPs provide for the patient? 1. How should they be fit (with specific numbers)? 2. What are the effects of these lenses being worn over time? 3
- provides add
- high eccentricity back surface must be fit steep (BC of 1 to 6 D steeper than K, Power 1 to 6 D different than spec Rx)
- mold the cornea to make it more myopic
If a GP lens is riding high, what should be done?
- steepen BC by 0.10mm
- specify thin lens design
- reduce lens diameter
If poor distance vision is occurring in a translating design, what should be done?
- truncate to lower segment
- increase OZD
- lower seg height
What are the advantages to Modified Monovision?
- May allow monovision or multifocal failures to continue wearing CLs
- Better stereopsis than monovision
What are the advantages to multifocal lenses?
- binocularity maintained
- glasses not needed at distance or near
- amblyopia/monocular able to fit
Does an increase in eccentricity increase or decrease power change?
increase
Are aspheric front surfaces better for low or high adds?
low (up to +2.25)
If near vision is decreased due to over-minusing at distance, what is the solution?
carefully OR and push plus
What are the advantages of alternating vision lenses?
- clearer vision at distance and near than with simultaneous designs
- best optics of any multifocal design
What are the advantages to using distance CL and near specs?
- optically clear at distance and near
- cost (less chair time for Dr.)
- cost for patient
What are the key characteristics of a patient that would be best for a simultaneous vision MF lens?
- low lower lid
- looser lids
- accept slight visual compromise
- little residual astig
- usually IP, some LA
What specific types of multifocal lenses are center distance?
- Acuvue Oasys for Presbyopia (Vistakon)
– Proclear EP (CooperVision)
What percent of the time should there be very good vision with multifocal and monovision lenses?
80%
How should a change from an over-refraction be handled by the doctor for a monovision patient?
- use trial lenses
- check change with of proper eye at both near and distance and let them know that this is the change you are g`oing to make to make sure they want it
If poor translation is occurring in a translating design, what should be done?
- flatten BC
- increase prism ballast
- truncate
- raise segment height
What are the key characteristics of a patient that would be best for a alternating vision MF lens?
- large pupil size
- good lid tension
- high add (near) and critical distance
- moderate residual astig