Anisometropia: When Each Eye Has a Different Prescription
Quick answer: Anisometropia means the two eyes have a significantly different prescription, usually a difference of 1.00 diopter or more. Adults may notice eye strain, headaches or images of different sizes (aniseikonia) in glasses. In children it is a leading cause of amblyopia (lazy eye) because the brain favours the clearer eye, so early detection and correction are important. Contact lenses often work better than glasses for large differences.
Noticed this in your own eyes? Book an eye examination (NPR 400) with an optometrist at Vision Concern Lazimpat, Boudha-Tushal or Makalbari. WhatsApp +977 9841466716.
Related service: Children's eye examinations at Vision Concern Lazimpat, Boudha-Tushal and Makalbari.
Why it matters
When one eye focuses much better than the other, the brain may ignore the blurrier image. In young children this stops normal vision developing in that eye. Because the child can still see well with the good eye, the problem is often missed without an eye test.
Symptoms in adults
- Eye strain or headaches
- Discomfort or dizziness with new glasses
- Objects looking a different size with each eye
- Poor depth perception
Correction options
- Glasses, sometimes with design tweaks to reduce size differences
- Contact lenses, which reduce image-size difference for large powers
- Patching or atropine treatment for amblyopia in children
- Refractive surgery in selected adults, after a specialist assessment
When to get urgent care
Seek prompt care for any sudden change in vision in one eye, and have children with a family history of lazy eye or squint checked early.
How Vision Concern can help
Vision Concern optometrists in Kathmandu can examine your eyes, record what they find for comparison, update your glasses or contact lenses, and refer you to an ophthalmologist or eye hospital when medical treatment is needed. Vision Concern does not perform surgery or injections.
Frequently asked questions
How much difference is anisometropia?
A difference of about 1.00 diopter or more between the eyes is usually called anisometropia.
Can anisometropia cause lazy eye?
Yes. It is one of the most common causes of amblyopia in children.
Are contact lenses better for anisometropia?
For large differences, contact lenses often give more comfortable vision than glasses.
This guide is general information from the Vision Concern editorial team. It is not a diagnosis and does not replace an eye examination or medical advice.
Yes. Many visitors, particularly from Bangladesh and West Bengal (Kolkata), come to Nepal for cataract, retina, or other eye surgery at a hospital and also want new glasses, a general eye exam, or contact lenses at the same time, before or after their procedure. Vision Concern is an optical and eye-examination clinic, not a surgical hospital, so we work alongside hospitals such as Tilganga: we are happy to see you for glasses, contact lenses, or a routine check-up either side of your surgical treatment elsewhere.
No conversion is needed. Eyeglass prescriptions from Germany, France, the UK, the USA, China, Russia, and almost every other country use the same international format, SPH (sphere), CYL (cylinder), and AXIS, measured in diopters. Our opticians read this directly, so you can bring your prescription paper, a photo of it on your phone, or simply your current glasses, and we will use the same values. If your prescription is more than a year or two old, we recommend a quick, free re-check before we make your new pair.
Yes. Above roughly 3,000 metres, UV exposure increases sharply because of the thinner atmosphere and reflection off snow, and ordinary sunglasses (category 2-3) do not block enough UV to prevent snow blindness (photokeratitis). We recommend glacier glasses or category-4 sunglasses with side shields, and can fit these with your own prescription if needed. Vision Concern offers ZEISS polarized, UV400-certified sunglasses with prescription lenses, which we can prepare before you set off on your trek.