Why does sustained close-up work induce eye strain, involving ciliary muscle fatigue, more readily in a dimly lit room versus a brightly lit one?

💡 Explanation

In dim light, increased pupil dilation reduces the depth of field, requiring greater accommodative effort from the ciliary muscles to maintain focus at near distances, stimulating the accommodation-convergence reflex to a greater extent; therefore, sustained close-up work under dim light results in increased eye strain, rather than other options linked to retinal processes.

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