What is Astigmatism?
Astigmatism is a common vision condition that causes blurred vision. It occurs when the cornea (the clear front cover of the eye) is irregularly shaped. This causes light to focus on more than one spot on the retina (the light-sensitive tissue at the back of the eye), resulting in distorted or blurred vision.
Types of Astigmatism
There are different types of astigmatism:
- Myopic Astigmatism – Nearsightedness combined with astigmatism. Objects further away appear blurry.
- Hyperopic Astigmatism – Farsightedness combined with astigmatism. Close-up objects appear blurry.
- Simple Astigmatism – Astigmatism without nearsightedness or farsightedness.
- Irregular Astigmatism – Occurs after eye injury or surgery.
Common symptoms of astigmatism include:
- Blurry or distorted vision at all distances
- Difficulty seeing road signs, TV, computer screens, etc. clearly
- Headaches and eye strain
- Squinting or tilting head to see more clearly
- Fatigue and trouble concentrating due to eye effort
If you experience any of these vision symptoms, see an eye doctor who can diagnose astigmatism with an eye exam.
Do Glasses for Astigmatism Have to Be Thick?
The thickness of astigmatism glasses depends on the degree of the correcting prescription. Individuals with mild astigmatism can often wear relatively thin lenses. However, for higher astigmatism prescriptions, thicker lenses may be required to properly correct vision.
Here are some general guidelines on astigmatism glasses thickness:
- Mild Astigmatism (Less than 1.00D) – Usually thin lenses
- Low Astigmatism (1.00D to 2.00D) – Medium lens thickness
- Moderate Astigmatism (2.25D to 4.00D) – Moderately thick lenses
- High Astigmatism (Over 4.00D) – Very thick, heavy lenses
As the astigmatism prescription increases, so does the thickness and weight of the lenses required. However, there are lens options that can help minimize thickness even for stronger prescriptions, which will be discussed later.
Factors Affecting Astigmatism Glasses Thickness
Several factors impact how thick glasses lenses will be for an astigmatism prescription:
Degree of Prescription
The stronger the astigmatism correction required, the thicker the lenses will be. Higher prescriptions require thicker lenses to properly focus light and correct vision distortion.
High index plastic or polycarbonate lenses are thinner and lighter than standard plastic CR-39 lenses. Although they cost more, high index lenses are recommended for stronger astigmatism prescriptions to maintain cosmetic appeal.
The lens design can account for prescription in the thinnest area of the lens. Aspheric and atoric lens designs specifically for astigmatism can optimize lens thickness.
Added lens treatments like anti-reflective and scratch-resistant coatings can slightly increase lens thickness.
Eyeglass Frame Size
Larger lens sizes required in oversized frames can make lenses seem thicker. Smaller eyeglass frames optimize lens thickness.
Prescription Difference Between Eyes
A large difference in astigmatism prescription between eyes may increase lens thickness in the eye requiring greater correction.
Tips for Thinner Astigmatism Glasses
Here are some tips for minimizing the thickness and weight of eyeglasses needed to correct your astigmatism:
Ask For High Index Lenses
High index plastic or polycarbonate lenses have a greater light-bending power, allowing thinner lens materials to be used.
Select Smaller Frames
Frames with a smaller lens size require less lens material to cover the eye, optimizing thickness.
Get Lens Optimization
Specialized lens designs and customizations for astigmatism during the lens manufacturing process can improve thickness.
Upgrade to Aspheric/Atoric Lenses
These lens designs specifically correct astigmatism using less lens material.
Avoid Unnecessary Lens Treatments
Extra lens coatings like photochromic lenses (get darker in sun) and anti-reflective coatings increase thickness slightly. Only get essential treatments.
Ask About Edge Polishing
Polishing and thinning the edge of the lenses makes them seem less thick cosmetically.
Consider Contact Lenses
For very high astigmatism prescriptions, gas permeable contact lenses may provide better vision correction and comfort compared to very thick glasses.
Do Glasses Correct Astigmatism Completely?
With the proper prescription, astigmatism can be corrected very effectively with glasses. However, it takes getting an accurate eye exam and having the glasses properly fitted to optimize the vision correction.
Here are some factors that allow glasses to fully correct astigmatism:
- Comprehensive eye exam to determine exact refraction and prescription needed
- Precision of lenses during manufacturing
- Proper alignment of lenses in frames for accurate positioning
- Adjustments made to frames to fit lenses correctly
- Wearing glasses consistently so vision stays corrected
After an initial adjustment period, astigmatism glasses should provide crisp, clear vision at all distances when worn consistently. If vision through the new glasses still seems blurred or distorted, return to your eye doctor for a prescription check and adjustment.
With today’s accurate diagnostic technology and advanced lens capabilities, eyeglasses can effectively correct even high degrees of astigmatism.
What is the Strongest Astigmatism Prescription?
The measurement unit for astigmatism prescriptions is called diopters (D). Here’s an overview of how astigmatism prescriptions progress from mild to very high:
- Mild Astigmatism – 0.50D to 1.00D
- Low Astigmatism – 1.25D to 2.00D
- Moderate Astigmatism – 2.25D to 4.00D
- High Astigmatism – 4.25D to 8.00D
- Very High Astigmatism – Over 8.00D
The highest documented astigmatism prescriptions exceed 20.00 diopters. However, prescriptions over 10.00D are extremely rare. Having over 6.00D of astigmatism typically interferes significantly with uncorrected vision.
The strongest astigmatism correction that can be worn in glasses is around 10.00D. Any prescription stronger than this would result in lenses too thick and heavy to be usable.
For the highest astigmatism amounts over 8.00D, specialized gas permeable contact lenses often correct vision better than eyeglasses. But glasses remain effective at correcting most degrees of astigmatism.
Astigmatism Glasses Frame Selection Tips
Choosing eyeglass frames with astigmatism requires some special considerations:
- Select small, rounded frames to minimize lens size
- Plastic frames accommodate thicker lenses better
- Go for light metal frames like titanium if you prefer metal
- Make sure frames can handle extra lens thickness
- Adjustable nose pads aid fitting thicker lenses
- Temples should have adjustable length for a secure fit
- Consult your optician to determine suitable frames
An eyeglass frame that fits and positions lenses optimally is important for getting the full astigmatism correction. Discuss frame selection with your optician to find the best model for your prescription strength and facial features.
Kids’ Astigmatism Glasses
Many children are diagnosed with astigmatism and prescribed eyeglasses. Here are some factors affecting glasses prescribed to correct astigmatism in kids:
- Kids typically have lower astigmatism prescriptions below 4.00D
- Minimal lens thickness needed for children’s weaker prescriptions
- Plastic frames in smaller child sizes accommodate lenses well
- Polycarbonate lenses are safest for kids’ glasses
- Durable frames that can withstand play and activity are best
Fortunately, kids’ astigmatism prescriptions can usually be filled in children’s eyeglass frames with thin, lightweight lenses. This prevents the glasses from being too bulky or heavy.
Making glasses comfortable and appealing looking helps ensure kids with astigmatism wear them consistently to correct vision development.
Mild to moderate astigmatism can generally be corrected with reasonably thin, lightweight eyeglass lenses. However, higher prescriptions over 4.00D may require thicker lenses, depending on the specific prescription.
Advanced lens materials like high index plastic and optimization for astigmatism help minimize thickness. With an accurate prescription and proper fitting, glasses can correct even high degrees of astigmatism effectively.
See an optician to determine the optimal lenses and frames specifically suited to your astigmatism and prescription strength. With current optical technology, attractive and comfortable glasses for astigmatism are readily achievable.