New Glasses Feel Wrong? Prescription, Fit and Adaptation Checks
New glasses can feel unfamiliar, but discomfort does not automatically mean the prescription should be increased or reduced. The written prescription, the lenses made from it, the frame position and eye health all deserve consideration. This guide explains what to ask for at a recheck; do not alter prescription numbers yourself.
Understand the prescription before comparing it
- SPH: spherical power, commonly minus for myopia and plus for hyperopia.
- CYL and axis: amount and orientation of astigmatism correction.
- ADD: extra near power for a prescribed purpose, often in bifocal or progressive lenses.
- PD: pupil distance used for lens centration; it is a fitting measurement, not a refractive power.
Prescriptions can be written in plus-cylinder or minus-cylinder notation. Numbers may look different while describing equivalent optics, so ask the dispenser to compare them correctly.
At the recheck: separate three questions
- Were the lenses made correctly? Ask for lens power, cylinder axis and any prism to be checked against the order.
- Are the lenses positioned correctly? Frame slip, tilt, centration and fitting height matter. Progressive lenses need fitting measurements for the chosen frame; a ruler-and-mirror PD estimate does not replace that assessment.
- Is the prescription still appropriate? If lens verification and fit do not explain symptoms, a refraction and eye-health review may be needed.
Describe the problem precisely
Bring old and new glasses plus both prescriptions if available. Note whether blur occurs at distance, computer or reading range; whether one eye or both are affected; and whether it changes after blinking or moving the frame. Measure your usual screen or reading distance for the appointment. This gives the examiner more useful information than simply saying the glasses are “too strong.”
Adaptation without forcing unsafe vision
Follow the wearing advice given for your lenses. Mild unfamiliarity may improve, but marked blur, worsening headache, nausea or persistent imbalance warrants an earlier recheck. Do not drive or use hazardous machinery while vision or balance is unreliable, and do not assume every problem must be endured for two weeks.
Choose lens features for the task
Single-vision, bifocal and progressive lenses serve different viewing needs. Photochromic lenses change tint with lighting conditions. Blue-light filtering is not a proven solution for all digital eye strain: a Cochrane review found little or no short-term advantage over non-filtering lenses for computer-related visual fatigue. Accurate correction, working distance and comfortable lighting remain practical points to review.
When it is not a routine glasses problem
Sudden vision loss, new flashes or many floaters, a dark curtain, severe eye pain or new double vision require prompt medical attention rather than a routine optical adjustment.
Related: how refraction and PD are measured and how to record a recent vision change.
Sources and review
Reviewed October 27, 2026. Educational information; individual diagnosis and treatment require an eye examination.