Dilating eye drops at a children’s eye examination
Information for patients from the Orthoptic Department
A paediatric ophthalmologist or optometrist has asked that your child be given eye drops before their eye clinic appointment. This leaflet explains for following.
Why your child needs the eye drops.
How the eye drops are given.
What the possible side effect are.
We hope this leaflet answers some of the questions you may have. If you have any further questions or concerns, please speak to the clinician caring for your child.
Why do we need to use dilating eye drops?
Eye drops relax the muscle in the eye that controls the size of the pupil (the black part of the eye). This gives the clinician (ophthalmologist or optometrist) a larger window to look through to check the health of the eye.
When a test for glasses is carried out, the eye drops will relax the focusing muscles of the eye. This allows the clinician to measure what prescription glasses are needed more accurately.
There is no alternative to eye drops if your child needs a detailed and thorough examination of their eyes.
These are the most common eye drops used.
Cyclopentolate
Tropicamide
Phenylephrine
Atropine
How will the eye drops be given?
The clinician will administer the eye drops at the start of your child’s appointment.
Whilst the drops are given, some children choose to sit upright, with their head tilted back. Other children may prefer to have a cuddle and lie across their parent’s lap with their head supported. Both positions are fine, it is up to the child. The parent stays with the child during their appointment.
Once your child is comfortable, the clinician will create a pocket by gently pulling your child’s lower eyelid away from the surface of the eye. One drop will be put into this pocket. Your child can then blink and wipe their eyes with a tissue.
To allow the eye drop to be instilled, some younger children may need help to keep their eye open. The orthoptist will gently open the eye if needed.
Eye drops can feel very cold or sting a little, but this will only last for 10 to 20 seconds.
If your child has particularly dark eyes they may need a second eye drop.
How long do the eye drops take to work?
It takes at least 30 minutes for eye drops to work fully. We will ask you and your child to wait in the waiting area while the drops take affect.
How will dilating eye drops affect my child’s vision?
Eye drops can make your child’s vision blurry, especially for near-sight tasks such as reading.
Once the pupils have dilated (become large) they will be more sensitive to light. During this time, your child may feel more comfortable wearing a cap, hat, or sunglasses to protect their eyes from bright sunlight.
It can take 4 to 8 hours for the blurriness to wear off, but pupils might still be larger than normal the next day.
When can my child return to their normal activities?
If they feel able to, children can return to their normal activities after their appointment. If they go back to school after having eye drops, tell their teacher as their eyesight may still be blurry.
Is there anything I need to tell the clinician before the eye drops are given?
Before the orthoptist gives your child the eye drops they will ask you some questions about your child’s health. Here are some examples of the questions they may ask you.
Is your child allergic to anything?
Have they had a reaction to eye drops in the past?
Does your child have a heart condition or high blood pressure?
Do they have any other health conditions?
Please give as much information as possible, as some eye drops affect the health conditions listed above. If you have any questions or concerns, please speak to the orthoptist.
Are there any side effects to using eye drops?
All medications can cause side effects, although not everyone experiences them.
Common side effects (affect between 1 in 10 and 1 in 100 people). Eye irritation, temporary blurred vision, or flushed cheeks.
Rare side effects (affect between 1 in 1000 and 1 in 10,000 people). Rapid heart rate, dry mouth, high temperature, or raised pressure inside the eye.
A serious allergic reaction is very rare (affects less than 1 in 10,000). Please tell your clinician immediately if your child experiences:
a rash / itching
swelling of their face / tongue / neck
extreme dizziness, or
has trouble breathing.
If your child experiences a serious allergic reaction ask for urgent medical help from your clinician. If your child experiences these side effects outside the hospital, call 999 for an ambulance or go to the Emergency Department.
Contact details
If you have questions or concerns about dilating eye drops, please contact the Orthoptic Department. If we are not available, please leave a message with your child’s name, hospital number or date of birth, and your contact number if you would like us to call you back.
Orthoptic Department
Telephone: 01227 868615
References
[Web sites last accessed 13 February 2026]
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