Cycloplegia

What is cycloplegia?

Cycloplegia is a temporary paralysis of muscles inside your eyes that control how your eyes focus. Cycloplegia happens with medicated drops that go on the surface of your eye. It’s temporary, and how long it lasts depends on the medication causing it and other factors.

The lens of your eye is flexible. Part of your eye, the ciliary body, contains muscles that can change the lens’s shape. That shape-changing process is called “accommodation.” It allows you to focus your eyes on things up close (like when you read a book, use your phone or look at a computer screen).

Accommodation is a reflex, so you can’t control how it happens. Sometimes, the accommodation reflex can cause issues or make certain conditions worse. That’s where cycloplegia is most valuable.

When is cycloplegia used, and why?

Cycloplegia has a few main uses:

• Temporarily blocking the accommodation reflex while an eye care specialist does an eye exam. One way that’s especially helpful is with diagnosing and measuring refractive errors.
• Temporarily paralyzing muscles inside your eyes during eye surgeries.
• Treating certain eye conditions, especially lazy eye (amblyopia) and specific forms of uveitis.

Several of the medications that cause cycloplegia also come in other forms or treat other conditions. So, cycloplegia can also happen as a side effect of these.

One key example of that is scopolamine, an antinausea medication in motion sickness skin patches. That’s why you should always wash your hands immediately after applying these patches. Medication residue on your hands can unintentionally cause cycloplegia that lasts up to a couple of days.

What are the advantages of cycloplegia?

Cycloplegia has several advantages. They are:

• It’s temporary. Once the medication wears off, your eyes return to normal without lingering effects.
• It’s noninvasive. The medications come in eyedrop form, making them easy to apply.
• It’s painless. The medications themselves don’t cause any pain. You might have some discomfort because your pupils can’t narrow to limit how much light enters your eyes. Most eye specialists provide sunglasses for your comfort while you wait for the medications to wear off.
• The number of treatment options. Several medications can cause cycloplegia. That means there are usually other options if you can’t take certain medications for some reason. And the treatment options also have specific strengths and limits, especially how long they last.

What are the side effects of cycloplegia?

Cycloplegia is specific to the ciliary muscles that help you focus your eyes. But the medications that cause cycloplegia also cause pupil dilation, so that’s the most common “side effect” of cycloplegia (though in many cases, like with eye exams, having both is useful).

Because cycloplegia also causes temporary pupil dilation, it’s common to experience:

• Light sensitivity
• Difficulty reading printed materials and screens up close (like books, newspapers, computers, tablets or phones)
• Headaches

Other eye side effects include:

• Stinging or burning sensation (this is usually very brief and mild)
• Eye redness
• Eye irritation

There are several other possible side effects of medications that cause cycloplegia, and these can vary by medication. Some of the longer-acting medications may have more severe side effects. Your eye care specialist is the best person to tell you what medication-specific side effects you’re most likely to experience and what you can expect from them.

How long does cycloplegia last?

Some medications can cause cycloplegia that lasts for days. That’s more helpful with conditions where the affected eye structures need time to heal or where the goal is to penalize one eye to help the other strengthen (like with lazy eye). Medications that cause cycloplegia include:

• Atropine: lasts seven days to 12 days
• Cyclopentolate: lasts up to 24 hours
• Homatropine: lasts one to three days
• Phenylephrine: lasts up to six hours
• Scopolamine: lasts three to seven days
• Tropicamide: lasts six to 24 hours

How can I take care of myself after treatment involving cycloplegia?

If you have short-term cycloplegia from an eye exam or other treatment, it’s a good idea to take it easy while you wait for the medication to wear off. The side effects of cycloplegia aren’t usually severe. Still, they can interfere with simpler tasks, especially if you spend a lot of time reading or working in front of a computer screen.

While you have cycloplegia, you also may not want to drive. Cycloplegia makes your eyes sensitive to light and unable to focus up close, making it harder to drive safely. You may also find it harder to do work or hobbies while the medication remains active.

In general, your eye care specialist can guide you on things you can do while you have cycloplegia and what should wait until it wears off. And when in doubt, wait it out. It’s better to hold off on some activities rather than risk an injury or another issue because of trouble seeing.

When should I see my healthcare provider?

If you have cycloplegia, the most likely reason is because of a medical treatment. Your eye care specialist can tell you more about specific side effects or issues that mean you need further medical attention.

The more serious side effects aren’t as likely with the most common cycloplegia-causing medications. Some of the more serious side effects that mean you should call your eye specialist or get medical care include:

• Behavior changes
• Changes in heart rate, especially fast heart rate (tachycardia)
• Confusion
• Low blood pressure (hypotension)
• Seizures
• Breathing too slowly or taking breaths that aren’t deep enough (respiratory depression)