Refraction and prescription stability
What is it? Careful measurement of the focusing error, sometimes with more than one method. Why is it considered? The treatment plan begins with an accurate refraction and a history of stability. What happens? You look at letters or targets while lenses and instruments help measure your prescription.
Contact-lens wear can temporarily influence measurements, so follow the clinic’s instructions before testing.
Corneal topography and tomography
What are they? Scans that describe corneal curvature and, depending on the device, elevation and thickness patterns. Why are they considered? They help identify irregularity, keratoconus risk and features relevant to treatment planning. What happens? You place your chin on a rest and look at a target while the device captures images.
A scan must be of adequate quality; repeating a measurement can be more useful than interpreting a poor one.
Pachymetry and corneal thickness
What is it? Measurement of corneal thickness, obtained through an appropriate imaging or contact method. Why is it considered? Laser treatment removes tissue, and the remaining corneal structure matters. What happens? The exact experience depends on the equipment; many modern methods are non-contact.
Thickness is interpreted alongside shape and the planned correction, not as a single standalone cutoff.
Tear film, pupils and slit-lamp examination
Dry-eye assessment considers symptoms and signs affecting the ocular surface. Pupil assessment may be relevant in selected cases. A slit lamp lets the doctor examine the eyelids, cornea, anterior segment and lens under magnification.
These tests can reveal reasons to treat another problem first or to avoid surgery.
Eye pressure and retinal evaluation
Eye pressure and retinal health contribute to a complete ophthalmic assessment. Dilatation may be advised, which can temporarily blur near vision and increase light sensitivity. Ask whether you should bring someone or avoid driving afterwards.
The exact workup varies. Your surgeon may add or omit tests according to your history and proposed procedure.
Medical information & sources
This page provides general patient education and does not diagnose candidacy or replace an ophthalmologist’s examination. Clinical content requires final treating-doctor approval before launch.