ABO NOCE Practice Test

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Prepare for the ABO NOCE Test with concise flashcards and multiple-choice questions. Each question includes hints and explanations, ensuring you're exam-ready!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

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What percentage of cylinder power is attributed to the axis of 90?

25%
50%
75%
100%

The correct answer is: 100%

The correct answer indicates that 100% of the cylinder power is attributed to the axis of 90 degrees. In the context of optometry and lens prescriptions, the axis refers to the orientation of the cylindrical power used to correct astigmatism. When a lens has a cylinder component, that particular power is mainly effective along its axis. In your example, if the axis is set at 90 degrees, all of the cylindrical correction provided by that lens (100% of it) is specifically geared towards correcting the astigmatism at that axis. This concept is critical in understanding how lenses function. A cylinder power isn't spread out evenly across all axes; rather, it is fully concentrated at the specified axis, maximizing its effectiveness for correcting vision. Other options imply a partial contribution to the cylinder power at the axis, which doesn’t accurately reflect how cylindrical correction operates.