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Contact Lens Conversion

Convert your glasses prescription to contact lenses.

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CYL and AXIS are only for Astigmatism (Toric lenses). If your prescription does not have these numbers, please leave those fields blank.

Sphere (SPH)

Cylinder (CYL)

Axis

Vertex Distance (mm)

OR

Curious how it works?

If you are interested in the math behind vertex distance and why your prescription changes, please read the detailed guide below.

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How to Read Your Astigmatism (Toric) Contact Lens Prescription

✨ Low Astigmatism Squad (CYL -0.25 to -1.00)? Click here! Astigmatism over -1.00? (e.g., -1.50)? Read the guide below! 👇

🛍️👁️ First Time Buying Toric Lenses at EyeCala? The Ultimate Guide!

Ready to ditch the glasses but confused by all the numbers on your prescription? 😵 We feel you. But don't stress! This guide is here to help you decode your script and order your EyeCala lenses like a total pro. 🚀✨

Still feeling unsure? You can always hit up our support squad at cs@EyeCala.com or contact us here!

1️⃣ Secure the Script (Get Your Prescription) 🧾👓

First things first: You need the receipts. Visit your local optical shop for an eye exam and get your written prescription. It needs to clearly show your Sphere (SPH), Cylinder (CYL), and Axis values for each eye.

2️⃣ The Sphere Power (SPH) Situation 👓

This is your main power. Here's the vibe on choosing the right one:

✅ Up to -4.00: Easy mode. Choose the exact number on your script. 👍
✅ Over -4.00 (-4.25 to -14.00): The physics change a bit closer to the eye. Use this conversion chart to adjust:

Glasses Prescription (SPH)	Reduce Contact Lens SPH by
-4.00 to -5.25	0.25
-5.50 to -7.00	0.50
-7.25 to -8.50	0.75
-8.75 to -10.00	1.00
-10.25 to -11.00	1.25
-11.25 to -12.50	1.50
-12.75 to -14.00	1.75

📌 Pro Tip: If your calculated number isn't available exactly, always round down (less negative). For example:

✅ Glasses SPH is -7.00? Go for -6.50 contacts.
✅ Glasses SPH is -7.50? Also go for -6.50 (since high power toric lenses usually jump in 0.50 steps).

⚠️ Real Talk: If the difference is more than 0.50 from your exact prescription, things might get a little blurry.

3️⃣ The Cylinder Power (CYL) Tea 👁️🗨️

This is the number that corrects the astigmatism. You want to match this as closely as possible.

✅ Pick the exact cylinder value if we have it.
✅ If your exact number is missing, pick the next lowest number.

⚠️ Heads Up: If you choose a cylinder value that's more than 0.50 off from your script, your vision might not be 100% crisp, especially at night.

4️⃣ The Axis Angle (Ax) 🧭

✅ If the axis is selectable: Pick the number closest to your prescription. ✔️
✅ If you can't choose the axis: Don't panic! Selecting 180° usually works for most standard fits. 🆗

5️⃣ Base Curve (BC) Basics ⚙️

Your script might not even list a Base Curve (BC). That's normal! Most people fit perfectly in an 8.6mm BC. 😊 Unless you know for a fact you need a special curve, 8.6mm is the safe bet.

📝 The TL;DR Checklist:

✅ Get that official paper prescription.
✅ Do the math on your Sphere power if it's stronger than -4.00.
✅ Match your Cylinder (or go slightly lower).
✅ Match your Axis (or default to 180°).
✅ Stick to 8.6mm Base Curve unless you're special (in a good way!).

🔍 Want the Deep Dive on Astigmatism?

If you're the type who loves to know exactly how it works, keep reading for the detailed breakdown below! ⬇️📚

📋 How to Decode Your Autorefractor Receipt

🔎 Example: TOPOON Printout

Note: See "VD=12.00"? That's just machine settings. Ignore it. ❌

👁️ Right Eye (OD)

Measurement	Sphere (S)	Cylinder (C)	Axis (A)
1st	-3.50	-0.50	30°
2nd	-3.25	-0.50	35°
3rd	-3.50	-0.50	30°
Average	-3.50	-0.50	30°

Spherical Equivalent (S.E.): -3.75

The Vibe: Right eye is nearsighted (-3.50) with a lil' bit of astigmatism (-0.50) at a 30° angle. ✔️

👁️ Left Eye (OS)

Measurement	Sphere (S)	Cylinder (C)	Axis (A)
1st	-3.25	-0.25	10°
2nd	-3.00	-0.25	5°
3rd	-3.00	-0.25	10°
Average	-3.00	-0.25	10°

Spherical Equivalent (S.E.): -3.25

The Vibe: Left eye is nearsighted (-3.00) with very mild astigmatism (-0.25) at a 10° angle. ✔️

👀 Pupillary Distance (PD)

PD: 66.5 mm (Mainly for glasses, but good to know!)

🛒 EyeCala Shopping Tips

✅ Match your order to the Average values on your receipt.
✅ Don't stray too far! If SPH is off by >0.50 or CYL by >0.25, things will get blurry. ⚠️
✅ 8.6mm Base Curve is the industry standard and works for 90% of our EyeCala fam.

Understanding your numbers ensures you get that crisp, high-def vision. Keep this guide handy when you shop EyeCala! 🌟👓🛍️

🌀 The Deep Dive: Toric Lens Prescriptions

🔖 Step 1: Know Your Acronyms

Don't let the letters scare you. Here is the cheat sheet:

✅ 👁️ <R> / OD: Right Eye.
✅ 👁️ <L> / OS: Left Eye. (Don't mix them up!)
✅ 📏 S (Sphere/SPH): The main power. Minus (-) is nearsighted, Plus (+) is farsighted.
✅ 🔍 C (Cylinder/CYL): The astigmatism part. Usually a negative number.
✅ 📐 A (Axis/Ax): The direction of the astigmatism (1° to 180°).

🛒 Step 2: Entering Info at EyeCala.com

When you're adding to cart, just match the boxes:

✅ Sphere (SPH): Enter your S value.
✅ Cylinder (CYL): Enter your C value.
✅ Axis: Enter your A value.

⚠️ Step 3: The Extra Details

✅ 🔄 Base Curve (BC): The shape of the lens. 8.6mm is standard.
✅ 📏 Diameter (DIA): How big the lens is. Usually 14.0mm - 14.5mm.

💡 Final Reminders

✅ Website guides are helpful, but your eye doctor is the boss. Always confirm your fit with a pro.
✅ Clean lenses = happy eyes. Don't skip the hygiene routine! 🚿👁️✨

👀 Low Astigmatism (≤1.00D)? The "Regular Lens" Hack! 🎉

🔖 The Hack Explained: If your astigmatism is mild (1.00D or less), you might not even need expensive toric lenses! You can use a math trick called the "Spherical Equivalent (SE)" to wear regular colored contacts comfortably.

The Formula: SE = SPH + (CYL ÷ 2)

Examples:
🔸 SPH: -2.00, CYL: -0.50 ➡️ SE = -2.25 (Buy -2.25 regular lenses)
🔸 SPH: -3.50, CYL: -1.00 ➡️ SE = -4.00 (Buy -4.00 regular lenses)

🤔 Wait, what is "Spherical Equivalent"?

Think of it as an average. It combines your nearsightedness and your astigmatism into one single number, so you can shop our huge range of regular EyeCala lenses.

🧮 Let's Do The Math (It's Easy)

Here is a real example:

Prescription	Value
Spherical Power (SPH)	-1.00D
Cylindrical Power (CYL)	-1.00D
Spherical Equivalent (SE)	-1.50D

The Steps:

First, divide CYL by 2: (-1.00 ÷ 2) = -0.50
Then add that to your SPH: -1.00 + (-0.50) = -1.50

Boom! You can buy -1.50 regular lenses instead of toric ones.

✅ Who is this hack for?

This works best if:

Your astigmatism is 1.00D or lower.
You want access to way more colors and styles.
You're okay with vision that is "good" but maybe not "perfectly HD" crisp.

⚠️ Real Talk: If your astigmatism is higher than 1.00D (like -1.25 or -1.75), please stick to Toric lenses. This hack won't give you clear vision.

📖 How to Shop with SE

🔍 Check Script: Find your SPH and CYL.
🧾 Calculate: Use the formula above.
👓 Shop: Pick a regular lens with that power.
👁️ Test: Try them out to make sure they feel good.

🌟 Final Thoughts

If you have low astigmatism, this math trick opens up a whole new world of EyeCala colors for you!

🔖 Quick Ref: SE = SPH + (CYL ÷ 2)

Your eye health is everything. If you're confused, ask your doc or email us at cs@EyeCala.com. Enjoy your new look! 🌈✨👁️

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