Yes, Vyvanse can potentially cause dry eyes as a side effect. It is not a commonly reported side effect by the manufacturer, but it is possible. If your child has been experiencing dryness since starting the medication or a change in dosage, it may be worth discussing with a healthcare professional. Using lubricating eye drops as a first step is a good idea, but if the issue persists or worsens, consulting a pharmacist for personalized advice, including potential dosage adjustments, would be recommended.