CSLB General Building (B) Trade Practice Test
Frequently asked questions
How many ABO Optician practice questions are here?+
A full bank of original ABO Optician practice questions across the official content areas, weighted like the real exam, with explanations. Free, no signup.
What is the ABO Optician exam like?+
About 100 questions, 120 minutes. Practice by topic here, then take the full timed mock exam to gauge readiness.
Are these the real exam questions?+
No. Every question is 100% original, written from public primary sources with explanations. We never copy real exam questions or paid prep material.
Can I study in Chinese or Spanish?+
PrepPass practice is in English, 中文 and Español. The official exam is in English — switch the question language to English any time to rehearse the exact terminology you'll see on test day.
Sample practice questions
A few real questions from this free bank, with full explanations. Use the practice tool above for the whole set.
- 1. Ophthalmic Optics
What is the focal length of a +2.00 D lens?
- a.10 cm
- b.25 cm
- c.50 cm
- d.200 cm
Answer: c
Explanation: Focal length in meters equals 1 divided by the lens power in diopters. 1 / 2.00 = 0.50 m, or 50 cm. A stronger plus lens would have a shorter focal length.
- 2. Ophthalmic Optics
If the distance Rx is -3.00 D and the add is +2.00 D, what is the total power in the reading portion?
- a.-1.00 D
- b.-5.00 D
- c.+2.00 D
- d.-3.00 D
Answer: a
Explanation: The near power equals the distance sphere plus the add. -3.00 + 2.00 = -1.00 D in the reading zone.
- 3. Ophthalmic Optics
A prism deviates light in which direction?
- a.Toward the base
- b.There is no deviation
- c.Toward the apex
- d.Along the axis
Answer: c
Explanation: Light passing through a prism bends toward the thick base, while the image seen through it displaces toward the thin apex. Prism power is measured in prism diopters.
- 4. Prescription Analysis
Transpose the Rx: +2.00 -1.00 x 090 into plus-cylinder form.
- a.+1.00 +1.00 x 180
- b.+3.00 -1.00 x 180
- c.+2.00 +1.00 x 090
- d.+1.00 -1.00 x 090
Answer: a
Explanation: To transpose: add the sphere and cylinder for the new sphere (+2.00 + -1.00 = +1.00), change the cylinder sign (+1.00), and rotate the axis 90 degrees (090 becomes 180). Result: +1.00 +1.00 x 180.
- 5. Prescription Analysis
Compensated (effective) power differs from the prescribed power mainly due to what?
- a.Frame color
- b.Lens tint
- c.Vertex distance and lens tilt
- d.Bridge size
Answer: c
Explanation: When a high-powered lens sits at a vertex distance or tilt different from where it was refracted, its effective power on the eye changes, so a compensated power is calculated to preserve the intended correction.
- 6. Prescription Analysis
Compensated power calculations are most critical when the fitted vertex distance differs from what?
- a.The frame PD
- b.The refracted vertex distance
- c.The seg height
- d.The base curve
Answer: b
Explanation: The refraction is done at a specific vertex distance; when the dispensed frame sits at a different vertex distance, the effective power shifts, so compensation restores the intended power at the eye.
- 7. Dispensing
High-minus lenses can be made cosmetically thinner at the edge by doing what?
- a.Increasing the base curve
- b.Adding pantoscopic tilt
- c.Using a higher-index material and edge treatments like a roll and polish
- d.Choosing a larger frame
Answer: c
Explanation: Higher-index materials reduce edge thickness for minus lenses, and a smaller frame plus proper decentration further reduces thickness. Rolling and polishing the edge improves the cosmetic appearance.
- 8. Dispensing
For a progressive lens, insufficient seg/fitting height (frame too shallow) causes what problem?
- a.Distance blur
- b.Too much add power
- c.Excess prism
- d.Not enough room for the reading zone, cutting off near vision
Answer: d
Explanation: Progressive corridors need adequate vertical depth; if the frame's B measurement is too small, the reading portion at the bottom is cut off, leaving the wearer with inadequate near vision.
- 9. Instruments & Regulatory
Under FDA regulations, all dress eyewear lenses sold in the United States must be what?
- a.Made of glass
- b.Tinted
- c.Impact resistant (capable of passing the drop-ball test)
- d.Polarized
Answer: c
Explanation: The FDA requires prescription and non-prescription dress lenses to be impact resistant, historically demonstrated by the drop-ball test, to protect wearers from lens shattering into the eye.
Source: FDA impact resistance
- 10. Optical Math
Using Prentice's rule, how much prism is induced when a +4.00 D lens is decentered 5 mm?
- a.1.0 prism diopter
- b.2.0 prism diopters
- c.20 prism diopters
- d.0.5 prism diopters
Answer: b
Explanation: Prentice's rule: prism (prism diopters) = decentration (cm) x power (D). 5 mm = 0.5 cm; 0.5 x 4.00 = 2.0 prism diopters.