ABO NOCE Practice Questions (2026) — Free Sample Questions with Answers

Answer: C

+0.50 −1.50 × 180: The axis was changed but the cylinder sign was not; plus-cylinder form must have a positive cylinder.

+3.50 +1.50 × 180: This subtracts the cylinder from the sphere the wrong way (2.00 − (−1.50)). The new sphere is the algebraic sum, +0.50.

+0.50 +1.50 × 180: Correct. New sphere = +2.00 + (−1.50) = +0.50; change the cylinder sign to +1.50; change the axis by 90° to 180.

−0.50 +1.50 × 090: The sphere sign is wrong and the axis was not rotated 90°.

Transposition: (1) add sphere and cylinder algebraically for the new sphere, (2) change the cylinder sign, (3) change the axis by 90°.

Answer: C

Recheck the frame fit and lens centration first: These symptoms are not caused by the eyewear, and delaying care to adjust the frame could cost vision.

Advise an eye exam at his next routine visit: These symptoms suggest a retinal tear or detachment, which cannot wait for a routine appointment.

Refer him for same-day eye care by an eye doctor: Correct. Sudden flashes, new floaters and a curtain-like shadow are warning signs of retinal detachment and need urgent evaluation.

Suggest anti-reflective coating to reduce the flashes: Flashes from retinal traction have nothing to do with lens reflections and cannot be fixed with coatings.

Flashes + floaters + curtain or shadow = possible retinal detachment: urgent, same-day referral to an eye care provider.

Answer: B

62 mm: This adds only one lens's decentration (4 mm) plus 2 mm; the formula uses total decentration (8 mm).

66 mm: Correct. Frame PD = 70; total decentration = 70 − 62 = 8 mm; MBS = 56 + 8 + 2 = 66 mm.

58 mm: This adds only the 2-mm allowance to the ED and ignores decentration.

72 mm: This is the frame PD plus 2 mm; frame PD is not part of the blank size formula in this way.

MBS = ED + (frame PD − patient PD) + 2 mm, which equals ED + 2 × (decentration per lens) + 2 mm.

Answer: B

+0.50 +1.00 × 090: This is the same lens in plus-cylinder form, but the question asks for the minus-cylinder reading.

+1.50 −1.00 × 180: Correct. Sphere = the more plus reading (+1.50); cylinder = +0.50 − (+1.50) = −1.00; axis = the wheel setting for the sphere lines, 180.

+1.50 +0.50 × 180: This records the second reading as the cylinder instead of the difference between the two readings.

+1.50 −1.00 × 090: Power is correct, but the axis is the wheel position when the sphere lines are focused (180), not 90° away.

Minus-cylinder lensmeter technique: focus the sphere lines at the most plus power (sphere and axis), then the cylinder lines; cylinder = second reading − first.

Answer: D

The fitting height is too high: A height that is too high puts the corridor in the distance line of sight, so the patient lowers his chin to see far.

The monocular PDs are about 1 mm too wide: A small horizontal error narrows the usable near zone but does not force the head back for reading.

The add power is too strong for him: Too strong an add makes the patient hold material closer; it does not lower the near zone.

The fitting height is too low: Correct. When the fitting cross is too low, the near zone sits too far down, so the patient raises his chin to bring it in line with his reading gaze.

Multifocal too low → chin up to read. Too high → chin down to see distance, or a complaint of blurred distance.

Answer: A

A 5/8-inch steel ball dropped from 50 inches without fracture: Correct. The FDA drop-ball test uses a 5/8-inch steel ball (about 0.56 oz) dropped 50 inches onto the lens.

A 1-inch steel ball dropped from 127 cm onto the frame only: The FDA test is on the lens, and the drop height is 50 inches with a 5/8-inch ball.

A high-velocity 1/4-inch steel ball fired at 150 ft/s: The high-velocity test belongs to ANSI Z87.1 safety eyewear, not FDA dress-eyewear rules.

A visual check for scratches before dispensing: Inspection is good practice but is not the impact-resistance test the FDA requires.

FDA dress eyewear: 5/8-inch steel ball from 50 inches. ANSI Z87.1 safety eyewear: tougher high-mass and high-velocity tests.