A core eye assessment in which refractive errors of the eye (myopia, hyperopia, astigmatism, presbyopia) are measured with autorefractor and retinoscopy, and the most suitable eyeglass or contact lens prescription is determined.
Indication
- Blurred vision, headache, eye fatigue and difficulty seeing far or near
- Decline in school performance in children, difficulty seeing the board
- First eyeglass prescription or verification of an existing prescription
- Prescription determination prior to contact lens fitting
- Pre-operative assessment for refractive surgery (LASIK, PRK, ICL)
- Vision follow-up in systemic conditions such as diabetes and hypertension
- Annual routine eye health check
Preparation
- Existing glasses and contact lenses are brought to the appointment
- Contact lens wearers should remove lenses 1-2 weeks before the examination (per physician advice)
- Current medications (especially eye drops) are reported
- Pupil dilation (cycloplegia) drops may be needed in young patients and at first examination; driving that day is not advised
- Previous eye reports, surgical and medical history are prepared
How it's performed
- Distance and near visual acuity are measured with a Snellen chart
- Objective refractive error is measured with autorefractometer
- Retinoscopy confirms the refractive error, especially in children and complex cases
- Subjective refraction is performed with phoropter or trial frame to find the prescription the patient sees most clearly
- Astigmatism axis and cylinder value are fine-tuned with Jackson cross-cylinder
- Full refraction may be repeated after instillation of pupil-dilating drops if needed
Post-procedure
- Eyeglass or contact lens prescription is issued for the determined power
- Annual routine follow-up; every 6-12 months in children
- 1-2 weeks of adaptation is normal when starting new glasses
- Near-vision prescription is updated as presbyopia develops in adults
- Continuously increasing prescription or persistent blurring warrants earlier review
Risks
- 4-6 hours of blurred vision and light sensitivity from pupil-dilating drops
- Rare allergic reaction to drops
- Headache or eye strain if the wrong prescription is issued
- Underlying eye disease may be missed during refraction alone, so a complete eye examination is required
FAQ
Is the refraction examination painful?
No. It is completely painless and quick. Only the pupil-dilating drops may cause a brief stinging sensation.
Is the autorefractometer measurement the final prescription?
The autorefractometer provides an objective starting point, but the final eyeglass prescription is determined after subjective refraction with the patient's active responses. Both measurements should be evaluated together.
Why are dilating drops needed in children?
Children have a strong accommodative ability; drops temporarily suspend this so the true refractive error can be detected. This method is especially important for identifying latent hyperopia and strabismus.
Does my eyeglass prescription change every year?
In children and adolescents the prescription may change yearly as the eye grows. In adults it is generally stable; presbyopia for near vision usually develops after age 40. Sudden or rapid changes may signal other eye conditions.
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