Starting ADHD Medication? Get a Baseline Eye Check First

A Medsafe Prescriber Update released this month puts a number on something eye-care clinicians have quietly watched for years: stimulant medicines used to treat ADHD — methylphenidate, lisdexamfetamine and dexamfetamine — can affect the eyes. Between January 2010 and May 2026, New Zealand received five reports of ocular side effects linked to these medicines: three cases of blurred vision and one of dilated pupils (mydriasis) with methylphenidate, and one case of blurred vision with dexamfetamine.

Five reports over sixteen years is a small number, and most people who take these medicines never have an eye problem at all. But Medsafe's update is a useful prompt for a simple, low-cost precaution: if you or your child are about to start — or are already taking — a stimulant medicine for ADHD, a baseline eye examination is worth having.

What Medsafe flagged

The update lists a range of possible ocular effects associated with stimulant ADHD medicines:

• Increased eye pressure (intraocular pressure) and glaucoma
• Acute angle-closure glaucoma — a genuine medical emergency, typically presenting as sudden, severe pain in one eye or a bad headache
• Dry eye symptoms: irritation, a gritty or foreign-body feeling, redness, blurred vision and general discomfort
• Blurred vision and double vision (diplopia)
• Difficulty focusing (accommodation problems)
• Dilated pupils (mydriasis)

The most serious of these, acute angle-closure glaucoma, happens when the drainage pathway inside the eye becomes blocked and pressure builds up rapidly. People with significant long-sightedness (hyperopia) are already more prone to narrow drainage angles, which is thought to raise their risk. Medsafe's advice to prescribers is that anyone with a history of raised eye pressure, glaucoma, or risk of angle closure needs careful assessment before starting one of these medicines, and ongoing monitoring after.

Why a baseline check makes sense

A prescriber can ask about eye history, but they can't measure your intraocular pressure, image your optic nerve and retina, or check your drainage angles — that's what an eye examination is for. Having those measurements on file before you start a stimulant medicine gives your optometrist and your prescriber something to compare against if any visual symptoms come up later, rather than trying to work out after the fact whether a change is new or was always there.

This is exactly what baseline imaging is good at. An OCT scan (optical coherence tomography) gives a detailed, reproducible picture of the retina, macula and optic nerve, and a comprehensive examination adds intraocular pressure measurement, an assessment of the drainage angle, and a check of tear film and general eye health. Together they build the reference point that makes any future change easy to spot early — while it's still straightforward to manage.

We can also check your glaucoma risk directly — including gonioscopy

Because raised eye pressure and angle-closure risk are both on Medsafe's list, it's worth knowing that Rose Optometry offers a full glaucoma assessment, not just a pressure check. Alongside intraocular pressure measurement, visual field testing and OCT imaging of the optic nerve, this includes gonioscopy — a quick, painless test where a small mirrored lens and a drop of local anaesthetic let your optometrist look directly at the drainage angle at the front of the eye. That's the exact structure that narrows or closes off in acute angle-closure glaucoma, so it's the most direct way to know whether your eyes are naturally more at risk before you start a medicine that can tip things over.

Our optometrists

Any of our therapeutically qualified optometrists can carry out this assessment: partners Jagrut Lallu and Jacqueline Rowe, and optometrists Emilie Lawson (Accredited Glaucoma Prescriber), Jason Shen, Anjali Hira, Stella Wong and Jessica Wood.

Our recommendation

If you're about to start a stimulant ADHD medicine, or you're already taking one and haven't had a recent eye check, we'd recommend booking a comprehensive eye examination with OCT imaging — and a full glaucoma assessment with gonioscopy if you have any personal or family history of raised eye pressure, glaucoma, or significant long-sightedness. It's a sensible precaution, not a sign that something is wrong — most people on these medicines have no eye problems whatsoever. But a baseline record is cheap insurance, and it means that if you do notice blurred vision, eye pain, dryness or any other visual change down the track, there's already a comparison point on file.

See your GP or prescriber urgently — don't wait for a routine eye appointment — if you ever experience sudden, severe pain in one eye or a bad headache while taking one of these medicines. That combination can indicate acute angle-closure glaucoma, which needs same-day medical attention.

Book a comprehensive eye examination (includes full pretest and imaging) with our team: new patients book here or existing patients book here.

This article is general information, not a substitute for individual medical advice. Decisions about starting, continuing or stopping ADHD medication should always be made with your prescriber. Source: Medsafe Prescriber Update, "Ocular adverse effects of stimulant medicines for ADHD," September 2026.