CYL in Eye Prescription: Does It Mean You Have Astigmatism?
Ever stared at your eye prescription and thought, “What does CYL mean on an Eye Prescription?” You’re not alone. The majority of individuals take one look at that odd figure next to the term CYL and continue on their way without realizing that it is directly affecting the way they perceive the world.
Hola, I am Laura, and in case you have astigmatism (or even the slightest suspicion about it), this number is a very big deal. CYL is not ordinary jargon. It is the solution to the weakening of vision that is caused by the irregular curvature of the eyes.
In this guide, I will give everything about CYL Mean on an Eye Prescription.
- What CYL means
- What is the best way to understand your prescription as an optician?
- Why does that number affect your glasses, contact lenses
What Does CYL Mean on an Eye Prescription?
CYL means Cylinder, and it is concerned with the magnification of astigmatism you require on your lenses. Astigmatism is a widespread problem when the cornea or lens of your eye is not round, and this situation leads to blurred or distorted vision.
When you are prescribed CYL, you have astigmatism, and the goal of the number is to tell us how much astigmatism correction your eye requires to clear things up.
So basically:
- CYL = The intensity of correction
- Axis = where they should be put in correction
How is CYL Measured?
CYL is measured in diopters (D), reading the same as the sphere (SPH), which treats nearsightedness or farsightedness.
- YL values can only be in 0.25 D increments
- The value can be positive (positive) or negative (minus)
- Negative CYL (-):
- Served to fix myopia (nearsightedness) and astigmatism.
- Positive CYL (+):
- Applied in the treatment of hyperopic (far-sighted) astigmatism.
The Further from Zero
The further that the CYL number deviates towards zero, the more that your eyes are impaired.
Examples:
- CYL: -0.50 → Very mild astigmatism
- CYL: -1.25 → Mild to moderate astigmatism
- CYL: -2.50 → A still greater correction is necessary
- CYL: +2.00 → increase to very big correction of farsightedness astigmatism
The thing is that the smaller the number, the more your eyes simply need a bit of assistance. The higher it is, the more disproportionate the cornea or lens is, and the stronger the lens must be corrected.
Where is CYL Located on a Prescription?
When you get Cyl values on your regular prescription, this is under the column of each eye:
| Eye | SPH | CYL | Axis |
|---|---|---|---|
| OD | -2.00 | -1.25 | 180 |
| OS | -1.75 | -0.75 | 170 |
- OD = Right eye (Oculus Dexter)
- OS = Left eye (Oculus Sinister)
- CYL = Amount of astigmatism correction
- AXIS = Direction (in degrees) of astigmatism
The Axis value is never left alone without the CYL because it tells us the orientation of the astigmatism we should correct (between 1 and 180 degrees).
Read Also: What Is a Normal PD for Eyeglasses? (Chart + DIY Guide)
When Will You See CYL on Your Prescription?
The CYL value will only appear in case you have an astigmatism. In case your eyes are regular and symmetrical, there will be no CYL value, or it may be written as follows:
- Plano
- 0.00
- Blank (—)
There is no need to correct astigmatism in these cases.
How CYL Affects Your Glasses or Contact Lenses
Astigmatism correction is a number that has a practical meaning; it determines how your glasses or contact lenses can be produced and how effective the correction of your vision will be.
1. Lens Customization
The lens has to be specially molded to rectify the Curve of your cornea, which is uneven. It is not something that can be performed with a standard spherical lens.
- Your lenses will be a type of toric, and this is a custom-made lens against astigmatism.
- Toric lenses can rectify an eye in a particular meridian or axis.
2. Visual Clarity and Comfort
When there is an insufficient correction of your astigmatism:
- Text may look blurry
- The lights can also be streaky or haloed
- You may have an increase in the number of headaches or eye strain
3. Contact Lens Fit
In the case of contact lenses, the value of CYL will indicate whether you need to use a toric contact lens that is specially designed to treat an astigmatism condition.
Toric lenses have:
- A specific orientation
- Axis alignment
- It has features of stability to stop rotation
4. Lens Thickness and Cost
A greater CYL means that thicker lenses can be produced.
- The more correction there is more curvature
- It may also cost more due to custom shaping
In case of the high CYL mark, do not be surprised because your lenses will cost more than the average.
Can CYL Change Over Time?
Yes, it can do that. Similar to the SPH, the CYL can also change with age or with a lifestyle change.
You might notice changes due to
- Aging
- Eye strain from digital screens
- Eye surgery (e.g., LASIK)
- Injuries or corneal disorders
Your glasses have a dynamic vision, and even slight adjustments of CYL can alter the clarity. This is the reason I would advise you to go and visit ophthalmologists annually.
FAQs
What is a normal CYL in the eye?
A healthy CYL = 0.00, and this means that your eye does not have any astigmatism or a little astigmatism that cannot be corrected. Even a small number indicates that there is some form of irregular curve at the surface of our cornea.
Is -0.75 CYL eyesight bad?
Not really. -0.75 CYL indicates that you have a mild astigmatism. It is not very serious and can be easily repaired with eyeglasses or contact lenses. Unless you are experiencing symptoms such as blurred vision or headache.
Is CYL +0.25 bad?
0.25 CYL is a very weak astigmatism. In the majority of cases, it does not need any intervention unless you feel uncomfortable or have distorted vision. Routine examinations allow monitoring such minor developments as this one.
How do I know if my eyesight is good?
Your eyesight will be classed as good when you can see clearly (with or without correction), have only the fewest of symptoms, and your prescription can be maintained with only the smallest changes over time.
Read Also: SPH in Glasses Explained: What Your Prescription Means
Final Thoughts
CYL in your eyeglass prescription may not appear to be a significant amount; however, it makes a colossal difference as regards how you view the world. Being knowledgeable about what your prescription means, particularly regarding the cylinder part, grants you the power to make more informed decisions with regard to wearing glasses.
Many people have it; it can be treated, and once you have the right lens, the problem is gone and everything is sharp and clear again.
