Astigmatism.
Blurry letters, tired eyes, or difficulty seeing at night? Astigmatism can affect vision at more than one distance. At iDoctor in Glendale Heights, prescription testing starts with understanding what you are experiencing.
What it means
A difference in how light focuses.
Astigmatism is a common refractive error. The cornea or the lens inside the eye has a curvature that causes light to focus unevenly. Nearby and distant objects may look blurred or distorted.
It can occur alongside nearsightedness or farsightedness. Mild astigmatism may cause few noticeable symptoms.
What you might notice
- Blurred or distorted vision
- Squinting to bring details into focus
- Eye strain or headaches
- Difficulty seeing at night
These symptoms can have other causes. An eye exam helps identify what is affecting your vision.
Regular and irregular astigmatism
Regular astigmatism has a consistent pattern of curvature. With irregular astigmatism, curvature varies less evenly across the cornea, so standard lens correction may not address all the blur. Dr. Sayed also assesses irregular astigmatism and discusses suitable vision-correction options and any further evaluation that may be needed.
More than one focusing direction
One regular pattern is shown. Focal positions vary.
Reference distance focus
The focusing directions meet together.
Regular astigmatism example
Two focal lines, with no common sharp focus.
Inner green arc: retina
One focusing directionPerpendicular direction
Careful prescription assessment
More than a single number.
- Cylinder power
- The amount of astigmatism correction.
- Axis
- The orientation of that correction.
Dr. Saher Sayed considers your test results together with your responses during lens comparisons.
We schedule 30-minute eye exam appointments to make room for your concerns and questions. Tell us what feels unclear in your current glasses and which tasks matter most to you.
Describe your day
Bring your current glasses and discuss reading, screens, driving, and any persistent blur.
Compare the lenses
Your answers help guide prescription refinement; let the doctor know when two choices look similar.
Understand your options
We explain the prescription and discuss glasses or contact lenses in the context of your needs.
Share specifics if your current glasses have never felt quite right. Let us know whether the blur is constant, whether one eye seems different, or whether certain distances are more difficult.
Your correction options
Lenses chosen for you.
Common questions
A few helpful answers.
Does every case need correction?
Not always. Mild astigmatism may not require correction. Your doctor considers your measurements, symptoms, and vision needs.
Does a higher axis number mean stronger astigmatism?
No. Axis describes orientation, rather than strength. Cylinder power describes the amount of astigmatism correction.
Can astigmatism change over time?
Yes. It may increase, decrease, or remain stable. Eye exams help monitor changes and determine whether your prescription needs updating.