What is Segment Height (SH) and Why Does It Matter?
When it comes to custom eyewear, precision is everything. Segment height (SH) is one of the most critical measurements for multifocal and progressive lenses. At ZANYLEN, we believe in educating our customers about their eyewear to ensure the perfect fit. So, let’s break down what segment height is, why it’s important, and how you can measure it at home.
What is Segment Height (SH)?
Segment height is the vertical distance measured from the bottom edge of your lens (not the frame) to the center of your pupil. This measurement is taken in millimeters and is essential for properly positioning the progressive addition or bifocal segments in your lenses.
Unlike single-vision lenses, which don’t require this measurement, SH ensures that multifocal or progressive lenses function as intended, aligning perfectly with your natural line of sight. Each SH measurement is unique to the wearer, and even a small deviation can affect the clarity and comfort of your vision.
Why is Segment Height Important?
- Enhanced Vision: Accurate SH ensures that the transition zones in progressive lenses align with your visual needs.
- Comfort: Proper positioning of the segments reduces the need for head tilting or constant readjustments.
- Tailored Fit: SH varies with frame style and fit, meaning a one-size-fits-all approach simply doesn’t work for multifocal lenses.
Getting this measurement right isn’t just about convenience—it’s about optimizing your visual experience.
How to Measure Segment Height at Home
You don’t always need a professional to measure SH. With the right tools and a bit of patience, you can do it yourself at home. Here’s how:
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Gather Supplies:
- A ruler with millimeter markings (or a centimeter ruler you can convert to millimeters).
- A well-lit mirror.
- Your current glasses.
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Set Up:
- Put on your glasses and stand about 8 inches (20 cm) from a mirror that fully reflects your face.
- Make sure your glasses are sitting comfortably and naturally on your nose.
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Measure:
- Hold the ruler vertically against the lens, aligning the zero mark at the bottom edge of the lens (not the frame).
- Stare straight into the mirror and read the measurement that lines up with the center of your pupil.
- Repeat this process several times to ensure accuracy.
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Record the Measurement:
- If possible, ask a friend to help. Consistency is key, and a second set of eyes can help confirm the result.
Important Notes on Segment Height
- SH can vary between different frames, so always measure for each new pair.
- For bifocals, SH is measured from the bottom of the lens to the top of the lower eyelid.
- Even if you’re slightly off in your measurement, small differences are unlikely to impact your vision significantly.
ZANYLEN: Customizing Your Vision Experience
At ZANYLEN, we’re committed to ensuring your glasses are as unique as you are. Our custom eyewear options include:
- Adjustable nose pads and anti-slip ear hooks for comfort.
- Precision measurements like SH to match your exact needs.
- A step-by-step guide to help you measure and understand your eyewear.
If you have any questions about segment height or need further assistance, our dedicated team is here to help. Trust ZANYLEN for your eyewear needs—where comfort and clarity meet innovation.
Ready to experience custom comfort? Start your journey with ZANYLEN today!
