Podcast
Questions and Answers
What is the primary benefit of using antireflective coatings (ARCs) on lenses?
What is the primary benefit of using antireflective coatings (ARCs) on lenses?
Which type of glare typically begins at around 3000 lumens?
Which type of glare typically begins at around 3000 lumens?
What is a consequence of using sunglasses without backside ARCs?
What is a consequence of using sunglasses without backside ARCs?
What happens to the eye in response to discomfort glare?
What happens to the eye in response to discomfort glare?
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At what luminosity does disabling glare typically occur?
At what luminosity does disabling glare typically occur?
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What is the primary advantage of using a short-corridor progressive addition lens (PAL)?
What is the primary advantage of using a short-corridor progressive addition lens (PAL)?
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What is typically the intermediate power of a trifocal lens in relation to the add power?
What is typically the intermediate power of a trifocal lens in relation to the add power?
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How does the vertical intermediate height of a 14 × 35 trifocal compare to traditional flat top trifocals?
How does the vertical intermediate height of a 14 × 35 trifocal compare to traditional flat top trifocals?
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What unique feature does a hard design PAL provide regarding peripheral astigmatism?
What unique feature does a hard design PAL provide regarding peripheral astigmatism?
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Which option best describes the adaptation of patients used to lined segments when using PALs?
Which option best describes the adaptation of patients used to lined segments when using PALs?
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Study Notes
Antireflective Coatings
- Antireflective coatings (ARCs) reduce glare from car headlights, improving night vision.
- ARCs can minimize surface reflection from surrounding objects.
- Older drivers may stop driving during evening hours due to disabling glare.
- The ocular surface of a sunglass lens can act as a mirror, causing reflections of the wearer's own eyes.
- Sunglass lenses should have a backside ARC to reduce these reflections.
Glare
- Discomfort glare occurs at approximately 3,000 lumens.
- Disabling glare occurs at 10,000 lumens and causes lower contrast.
- Examples of disabling glare include looking at a sunset or car headlights at night.
Progressive Addition Lenses (PALs)
- PALs should be considered for all mature patients.
- Image jump is a prismatic effect produced when the wearer is not viewing through the optical center of the segment.
- Image jump is most bothersome at the top of the segment.
- Patients may perceive image jump as a shift or altered position of the image.
Tints & Coatings
- Light levels reaching the retina of a healthy 60-year-old are approximately one third of the light reaching the retina of a 20-year-old.
- Older patients require more light to achieve the retinal illumination of younger patients.
- Antireflective coatings (ARCs) can increase light transmission up to 99% by reducing surface reflections.
- ARCs can help patients with aging eyes who experience reduced light transmission due to fluorescence and scatter.
- Polarized lenses should be prescribed for patients who spend time outdoors and desire visual comfort and clarity.
- They are available in virtually any lens material and multifocal lens design.
- Polarized lenses can enhance driving safety by reducing glare from the sun.
UV Radiation & Protection
- The mechanism of damage from UV radiation (UVR) is photochemical and thermal.
- UVR risk factors include aphakia, pseudophakia, cataracts, photosensitizing drug use, and sun exposure more than 8 hours daily.
- The phakic retina is more sensitive to UVR at 325 nm by a factor of 2.5.
Bifocal Segments
- The segment with its optical center farthest from the segment top induces base-up prism.
- This base-up prism neutralizes the base-down prism caused by the distance correction.
Slab-Off Lenses
- Slab-off lenses are indicated when the vertical prism effect is greater than 2 prism diopters, or when there is a significant difference in plus or minus power in the vertical meridian.
- Slab-off lenses can be inventoried by the laboratory as semi-finished lenses, which can reduce costs and delivery time.
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Description
This quiz explores the concepts of antireflective coatings, glare, and progressive addition lenses (PALs) in ophthalmology. Understand how ARCs can improve night vision and learn about the effects of glare on visual comfort. Additionally, discover the significance of considering PALs for mature patients and the issues surrounding image jump.
