What does the CA/C ratio measure?

What does the CA/C ratio measure?

• A. CA/C ratio is the amount of change in accommodation when we stimulate a given amount of vergence.
• B. CA/C ratio is the same as AC/A.
• C. CA/C ratio measures the change in vergence with accommodation.
• D. CA/C ratio is a neural signal unrelated to accommodation or vergence.

Answer: (A)

CA/C ratio measures how much accommodation changes as convergence is stimulated. In other words, it quantifies the accommodation response per unit of vergence (diopters of accommodation per prism diopter of vergence). This is different from the AC/A ratio, which describes how much vergence changes in response to a given change in accommodation. It’s also not a measure of vergence changing with accommodation, nor is it a neural signal unrelated to accommodation or vergence.

CA/C ratio measures how much accommodation changes as convergence is stimulated. In other words, it quantifies the accommodation response per unit of vergence (diopters of accommodation per prism diopter of vergence). This is different from the AC/A ratio, which describes how much vergence changes in response to a given change in accommodation. It’s also not a measure of vergence changing with accommodation, nor is it a neural signal unrelated to accommodation or vergence.