Toric Lenses Practice Test

These questions are part of the practice quiz. Start practicing

• In the Rx -7.00 -1.25 x 090, what is the cylinder power and axis?
• Who benefits most from the dynamic stabilization/thin zones/double slab-off method of stabilizing toric lenses?
• A medium cylinder toric lens provides stable VA between which misalignments?
• Which factor most influences the axis choice for a toric lens?
• Which of the following is NOT a standard toric cylinder power?
• True or False: Sphero-cylinder over-refraction (SCOR) can result in oblique crossed cylinder effect.
• How does the peri-ballast method stabilize a toric lens?
• Specialty toric lenses axis increments are every how many degrees?
• When selecting the cylinder, what rounding rule should you apply?
• What is the correct method to determine the rotation magnitude and direction of a toric lens?
• If the axis is tilted right or CCW, what should you do to the spectacle axis to compensate for rotation?
• When a toric lens is stable, what should you look for regarding rotation?
• Which parameter is adjusted last when selecting a toric lens?
• Which of the following is NOT an available toric cylinder power?
• Movement of more than how many degrees means we should switch lens designs?
• Which rotation degree corresponds to a predicted 70% success rate?
• Which instrument is used to assess rotation of toric lenses in practice?
• During SCOR, a 45-degree misalignment leads to which cylinder loss?
• What should we do instead of guesstimating rotation?
• What does the watermelon seed effect describe in toric stabilization?
• If the toric cylinder vector reduces to -0.50, what lens should you fit?
• For the prescription OD: -7.50 -1.00 x 175, which trial should you pull?
• In the old method, which statement best describes how results were obtained?
• How will a flat fitting toric contact lens return to axis?
• What are the advantages of the dynamic stabilization/thin zones/double slab-off methods used to stabilize toric lenses?
• What manual technique is used to assess toric lens stability?
• What was the old method for calculating crossed cylinder?
• A toric lens is most significant between ______ D and ______ D of cylinder.
• What term describes astigmatic refractive error that remains when a contact lens is placed on the eye?
• In the old method's crossed-cylinder calculation, which two powers are stacked?
• If the toric lens rotation allows for BCVA, what should you do?
• True or False: It is often difficult to find oblique/ATR astigmatism CLs.
• The prism ballast method may exhibit vertical imbalance when only one eye requires astigmatic correction.
• Why does prism ballast stabilize toric lenses?
• When performing a sphero-cylinder OR on a toric lens, you get an axis 90 degrees away from the contact lens. What does this indicate?
• Which aspect of toric lens rotation should be monitored to assess stability?
• What steps should you include when evaluating a toric lens?
• What is the typical prism power range used in prism ballast stabilization?
• For the prescription OD: -3.75 -1.75 x 085, which trial should you pull?
• Why don't oblique toric lenses have a great success rate?
• Which item is not listed as an improvement to toric CLs?
• In the cross-cylinder calculator approach, what is the role of diagnostic lens parameters?
• What is the order of selecting a toric contact lens?
• During a toric lens OR, what type would you perform if BCVA is worse than 20/20?
• A low cylinder toric lens provides stable VA between which misalignments?
• Which stabilization method is described as thinner and provides no prism orientation?
• If Becherer twist test results show inability to tolerate rotation before blur, what is the likely recommendation?
• Which statement best describes the change from the old method to the cross-cyl calculator method?
• What does SE stand for in SE CLs?
• If there is 10 degrees of misalignment when performing sphero-cylinder over-refraction, there is a loss of ____ cylinder correction.
• If there is 45 degrees of misalignment when performing sphero-cylinder over-refraction, there is a loss of ____ cylinder correction.
• How will a good fitting toric contact lens return to axis?
• If axis is known first, what is the next parameter to determine for a toric lens?
• What is the SE CLs Rx value given a spectacle Rx of -7.00 -1.25 x 090?
• How does the dynamic stabilization/thin zones/double slab-off stabilize toric lenses?
• If the toric lens marking is located at 6 o'clock, we should measure the deviation from vertical or horizontal?
• Which option best describes the axis orientation with the greatest overall toric lens success?
• After showing the SE Rx in the phoropter and the patient hates the prescription, what is the next step?
• A toric lens has markings at 3 o'clock and 9 o'clock. Which axis orientation should be used to assess rotation?
• At which rotation degree does the twist test indicate that the patient must accept compromise?
• What is the most common method of toric lens stabilization?
• Why do toric lenses need to be stabilized?
• A patient: Rx OD -1.00 -0.75 x 175; CL trial -1.00 -0.75 x 180; rotation 10 degrees CCW; what is the appropriate LARS compensation?
• Which stabilization method specifically adds four zones of thickness to the mid-periphery and uses thin zones?
• Movement of more than how many degrees will reduce acuity and prompt switching the toric lens design?
• What is the guideline for selecting the sphere of a toric lens?
• Becherer twist test: if the patient can withstand 15 degrees of rotation until blur, what is the anticipated success rate?
• Which activity is not listed among the recommended evaluation steps for a toric lens?
• How should you show the CLs prescription to the patient?
• Which statement about SCOR is true?
• Should the following patient be considered for a toric lens: -8.00 -1.00 x 180?
• The Rx -7.00 -1.25 x 090 should be fit in SE CLs. What is the CL Rx?
• Lens markings on a toric lens denote the location of which features?
• Toric stabilization can involve lenses with specific cylinder power and axis combinations.
• Movement of __________ degrees will reduced in reduced acuity and we should compensate with LARS.
• Which component is corrected by toric lenses in cases of significant astigmatism?
• If there is 30 degrees of misalignment when performing sphero-cylinder over-refraction, there is a loss of ____ cylinder correction.
• During SCOR, if the axis is oblique relative to the CL axis, what does this indicate?
• When can you perform a toric lens OR?
• Which rotation degree corresponds to a predicted 90% success rate in the twist test with a single-lens toric?
• Which stabilization method is noted for not relying on prism for orientation and stabilization?
• From which part of a toric contact lens is the rotation direction measured?
• During LARS, rotation toward the left requires which axis adjustment?
• Which statement about toric lens rotation performance is most accurate?
• Which statement best describes the axis types with the greatest success rate for toric lenses?
• After establishing the axis in toric lens fitting, which parameter is addressed next?
• Where and how long does stabilization of a toric lens occur?
• For the prescription OD: +4.50 -4.00 x 173, which trial should you pull?
• Toric lens markings typically correspond to which part of the lens?
• Becherer twist test: if the patient can withstand 5 degrees of rotation until blur, what is the anticipated result?
• What rotation degree yields 90% success rate with two lenses?
• What is the axis value in the toric prescription -7.00 -1.25 x 090?
• If a patient's refractive astigmatism is less than 25% of the spherical refractive error, what is the recommended action?
• Which statement describes how to compensate for rotation movement of 10-20 degrees?
• Becherer twist test: if the patient can withstand 10 degrees of rotation until blur, what is the anticipated success rate?
• Is it appropriate to guesstimate the rotation when determining magnitude and direction?
• What is used to assess lens orientation in situ?
• Which statement best describes toric lens markings?
• Which input is used by the cross-cylinder calculator to tailor the diagnostic lens?
• Which stabilization method is particularly effective for high myopes and ATR cylinder correction?
• When rounding the axis, which meridians are considered major?
• If the toric lens markings are located at 3 and 9 o'clock, the deviation should be measured from vertical or horizontal?
• If cylinder is low and sphere is high, which should be tried first?
• Why do toric lenses rotate?
• If the exact axis is not available, to which axis should you round?
• Which statement best supports using SE CLs over toric CLs for a patient with minimal astigmatism?
• Toric contact lenses tend to move _________ degrees with blinking.
• Toric lens rotation has more impact with lower/higher cylinder.
• During a sphero-cylinder over-refraction on a toric lens, if the axis matches the contact lens axis, what action is indicated?
• How does the prism ballast method stabilize contact lenses?
• Which statement best describes LARS?
• What does cross-cyl calculator consider to tailor the diagnostic lens?
• Which scenario supports using SE CLs rather than toric CLs?
• Which instrument is used in the old method to read results?
• What are the advantages of the prism ballast method?
• The cross-cylinder calculator recommends a diagnostic lens based on which factors?
• What improvement to toric contact lenses occurs?
• Should the following patient be considered for a toric lens: -1.00 -1.00 x 180?
• What is the guideline for selecting the cylinder of a toric lens?
• Should the prescription -7.00 -1.25 x 090 be placed in toric or SE CLs, and why?
• What are the advantages of the accelerated/blink stabilization design used to stabilize toric lenses?
• If a toric lens rotates up to 20 degrees with decreased acuity, what should we use?
• If the toric lens rotation is less than 10 degrees, what should you do?
• In prism/peri-ballast designs, which type has a lower average thickness?
• What is a disadvantage of the prism ballast method in toric lens stabilization?
• The peri-ballast method may have vertical imbalance if there is only one astigmatism CLs in one eye.
• During LARS, rotation to the left requires which axis adjustment?
• If the toric lens markings are located at 6 and 12 o'clock, we should measure the deviation from vertical or horizontal?
• What is the maximum cylinder power listed for toric lenses?
• Which strategy is used to compensate for toric-lens rotation by adjusting the axis?
• What is the primary reason oblique toric lenses have reduced success?
• Why can thickness changes used for toric lens stabilization be such a problem?
• How should we apply a toric lens?
• Lens markings will be in the same location regardless of axis or cylinder?
• What do toric lens markings indicate?
• What does LARS stand for in toric lens compensation?
• When performing a sphero-cylinder OR on a toric lens, you get the same axis as the contact lens. What does this indicate?
• Which of the following is NOT a stabilization option for toric contact lenses?
• When selecting a soft toric lens power, what is the correct order to determine the power?
• What is the typical recovery pattern for a well-fitting toric lens after rotation?
• For the prescription OD: -6.00 -2.25 x 175, which trial should you pull?
• Specialty toric lenses include what characteristics?
• Which statement best contrasts the old crossed-cylinder method with the cross-cyl calculator approach?
• What is the available sphere range for toric lenses?
• How does the accelerated/blink stabilization design stabilize toric lenses?
• What is the axis increment for toric lenses?
• If the axis is tilted left or CW, what should you do to the spectacle axis to compensate for rotation?
• If spectacle cylinder is greater than the corneal cylinder, which type of contact lens should be used?
• Which rotation direction is associated with adding to the spectacle axis?
• What test predicts soft lens success by twisting the cylinder knob in the phoropter until blur is observed on the chart?
• Which factor should be considered when selecting the axis of a toric lens?
• Toric lens cylinder powers are typically offered in what step size?
• If residual astigmatism is too high with a spherical lens, what lens is needed?
• True or False: After accounting for LARS, axis compensation changes the rotational characteristics of the lens.
• What is the dominant stabilizing component of toric lenses?
• A patient wears glasses with prescription OD: -1.25 -2.50 x 180 and OS -1.25 -0.75 x 180. When fit with soft toric lenses, the right lens rotates 15 degrees to the left and the left lens rotates 15 degrees to the right. Which eye would have the worse vision?
• If spectacle cylinder is less than the corneal cylinder, which lens is indicated?
• Statement: Toric lenses rotate 5 degrees or less in 80% of cases and 1 degree or less in 95% of cases.
• What complications are associated with toric lens stabilization techniques?
• What type of contact lens is typically required for irregular astigmatism?
• A patient with refractive astigmatism equal to or greater than what percent of spherical refractive error should be considered for a toric lens?
• What are the two methods of toric lens fitting?
• What term describes the slow drift of the axis markings in the same direction without blinking?
• Becherer twist test: if the patient can withstand 20 degrees of rotation until blur, what is the anticipated success rate?
• A high cylinder toric lens will/will not provide stable VA with any misalignment?
• What is the primary aim of using a cross-cyl calculator in toric lens fitting?
• During a toric lens OR, what type would you perform if BCVA is 20/20?
• Which cylinder power is a standard toric cylinder power?
• Toric lenses have sphere and cylinder set a specific axis.
• Which parameter is NOT used by the cross-cylinder calculator when recommending a diagnostic lens?
• Which description matches a toric lens that returns to axis quickly?
• Which stabilization method uses a minus carrier to prevent prism in the visual axis?
• Which outcome is the aim of stabilizing the cylinder axis in toric lenses?
• When performing LARS, what axis is altered?
• What is the primary purpose of toric lens markings when evaluating on the eye?