This is when the eyes are dilated using eye drops.  Certain dilating drops make the pupil larger, but they also paralyze the muscles inside the eye that control lens focusing. This paralysis is called cycloplegia. This effect is helpful when checking the vision in children (we call this cycloplegic refraction) as kids tend to “strain” when reading the eye chart.  Eliminating this strain through temporary “cycloplegic paralysis” gives a more accurate prescription. Cycloplegia can also be helpful for pain control in people with ocular inflammation, such as iritis or uveitis.  By paralyzing the muscles inside the eye, they don’t spasm as much around bright lights, which makes the eye more comfortable overall.  The cycloplegic drops we use in our office include tropicamide (most adults) and cyclopentolate (children). Atropine is the longest acting cycloplegic and was originally obtained from the belladonna nightshade plant – it was used in Victorian times to make women look “beautiful” by dilating their eyes. Most people have difficulty reading while dilated with cycloplegia drops.

Dr. Timothy Root is a practicing ophthalmologist and cataract surgeon in Daytona Beach, Florida. His books, video lectures, and training resources can be found at:


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