What is the most common use for anticholinergics in the eye?

Anticholinergics, when used in the context of ophthalmology, primarily function to cause cycloplegia, which is a paralysis of the ciliary muscle within the eye. This effect is important during eye examinations as it helps to relax the accommodation mechanism, allowing for a more accurate assessment of the refractive error. Cycloplegia facilitates thorough inspection of the internal structures of the eye by preventing the lens from changing shape, which would otherwise affect clarity and focus during the examination.

While dilation of the pupil can also be a consequence of anticholinergic use, the primary and more significant action relevant to the question is cycloplegia. Dilation alone does not address the need for muscle paralysis to effectively evaluate the eye's optical state. Therefore, the leading role of anticholinergics in eye care is indeed to induce cycloplegia, making the eye exam more effective and comprehensive.