5.3.2 Chooses, fits and manages the correction of presbyopic patients

What are over-spectacles?

Patient wears standard spherical / toric contact lenses for distance. Uses spectacles over the top for near work.

What are the pros and cons of over-spectacles?

Pros:

• Maintains crisp, uncompromised distance vision

• Easy adaptation

• Good option for when near tasks are occasional

Cons:

• Inconvenient

• Not a true “spectacle-free” solution

Who are Over-Spectacles Best for?

• Early presbyopes with minimal near demand

• Pts who prioritise sharp distance vision

• Pts comfortable juggling specs

What are Multifocal lenses?

Optics built into the lens give simultaneous vision at multiple distances. The brain adapts and selects the image of interest.

What are the pros and cons of multifocal lenses?

Pros:

• True spectacle independence for most activities

• More natural visual experience (good depth perception)

• Binocular correction at all distances

Cons:

• Some loss of contrast sensitivity

• Vision compromise

• Requires adaptation and patient motivation

Multifocal lenses are best for:

•Motivated patients not wanting to use glasses

• Pt’s with balanced distance / near visual requirements

How do Multifocal lenses work?

Centre-Distance

• Central optic zone = distance

• Surrounding rings = near / intermediate

Centre-Near

• Central optic zone = near

• Surrounding rings = distance / intermediate

Performance in Multifocal lenses depends on:

Pupil size

• Small pupils cause central zone to dominate

• Large pupils mean outer rings dominate

• Differences in lighting make a big difference

Neural adaptation

• Light from different focal lengths hit the retina simultaneously, creating multiple blurry and clear images. Brain adapts

What are Monovision lenses?

• Patient wears standard spherical / toric contact lenses for distance

• Uses spectacles over the top for near work

• DEMONSTRATE IN TRIAL FRAME FIRST

Monovision lenses are best for:

• Patients motivate to be spectacle-free

• Those with high astigmatism

Monovision

Pros vs Cons

Pros:

• Easy to fit

• Stable VA, even with high prescriptions

• Lower cost

Cons:

• Potential for intolerance as early presbyopes find it hard to suppress one eye

• Adaptation required

• Reduced stereopsis

• Poor intermediate VA

FINDING THE DOMINANT EYE

+1.25D lens in front of each eye.

The eye which has the best vision when the other is fogged = the dominant eye

If the same, choose thinnest lens to give best O2 transmission. Consider driving