Multifocal Considerations + Prescribing

What is the advantage of round bifocals?

nearly invisible, good cosmesis

What are the disadvantages of round bifocals?

large image jump

narrower reading field @ seg top

Who would be prescribe a round bifocal to?

patient previously in round bifocal

patient wanting invisible bifocal that can not adapt to PALs

What are the advantages of a flat top bifocal?

wider reading field near top

less image jump than round

can eliminate most displacement at reading level

What is the disadvantage to a flat top bifocal?

can see segment, bad cosmesis

Who do you prescribe flat top bifocals to?

patient currently wearing it

new bifocal wearer

What are the advantages to an executive bifocal?

widest reading field

no image jump

little total prismatic effect in minus lens

What are the disadvantages to an executive bifocal?

obvious segment

thick + heavy lenses

Who do we prescribe executive bifocals for?

patient currently in

patins who need large reading field

patients who are bothered by image jump or prismatic effects (if minus lens)

What is an advantage to a large round (round 40) bifocal?

can eliminate total displacement @ reading level for plus Lens

What is a disadvantage to a large round (round 40) bifocal?

large image jump

Who do we prescribe large round (round 40) bifocals for?

patient currently in

patient needing large reading field

hyperopic patient bothered by prismatic effects

What are the advantages to a PAL?

no image jump

continuous vision

no segment (good cosmesis)

What are the disadvantages to a PAL?

unwanted astigmatism

narrow reading field

increased cost

Who do we prescribe a PAL to?

patient currently in

patient in trifocals

patient needing intermediate vision

patient bothered by image jump

patient wanting invisible seg

Who are trifocals usually prescribed to?

people needing intermediate vision

people with advanced presbyopia (≥+2.00 add)

What are double segment bifocals?

segment at top and bottom of lens to provide near vision when looking overhead

Who do we prescribe double bifocals for?

occupations with close overhead work, especially if hyperope

What are occupational progressive lenses?

major lens is for intermediate viewing

bottom of lens for near viewing