Lens Guide
单光镜片示意图

Single Vision:

Single vision lenses are standard prescription eyeglasses.
Single vision lenses provide only one type of vision correction, with the same prescription strength across the entire lens. They can correct nearsightedness, farsightedness, or astigmatism. This is the most common type of lens.
• Either far • Or near
But ❌ not both at the same time.
👉 Like a camera with a fixed-focus lens.

渐进多焦点镜片示意图

Progressive:

Progressive lenses offer the closest thing to natural vision you can get in a pair of prescription glasses.They provide a smooth transition from near to far vision, incorporating all intermediate corrections to ensure clear sight at every distance.
• Top: Distance vision
• Middle: Computer / intermediate
• Bottom: Near / reading
The near-vision support comes from the ADD (Addition power).
👉 Like a camera lens with smooth zoom.

双光镜片示意图

Bifocal:

A bifocal lens means a lens with two credits of focus. A small portion of the eyeglasses lens is reserved for the near-vision correction. The rest of the lens is usually a distance correction.
• Top: Distance
• Bottom: Near (reading)
✔ Clear for far + near
❌ No smooth intermediate (computer) zone
❌ Visible line between the two parts👉 Like a camera with two fixed focal lengths.

阅读镜片示意图

Reading:

Reading lenses are prescription glasses designed for reading.
They provide optimal vision for reading or other close-up tasks, suitable for objects at reading distances ranging from 16 inches (approximately 40 cm) to 2 inches (approximately 5 cm).
If you notice your vision changing over time, struggle to focus on small print, or simply want to enhance eye comfort while reading, reading lenses can be highly beneficial.

Free Shipping on Orders Over $79
30-Day Returns & Exchanges
24/7 Live Online Customer Support

Knox

    Product form

    Transparent Grey Square Eyeglasses

    £9.00

    Halloween Lucky Draw
    Spin Now
    Size: Narrow
    Size Guide
    Frame:
    51-19-149
    Weight:
    25.4 g
    Frame Color: Transparent Grey
    Eydology Knox Clear Glasses 2 Eydology Knox Transparent Grey Glasses 1 Eydology Knox Light Green Glasses 1 Eydology Knox Dark Brown Glasses 1
      Free Shipping on Orders Over $79
      30-Day Returns & Exchanges
      24/7 Live Online Customer Support
      All prices include duties & VAT
      100% Prescription Accuracy Guarantee
      Free Remake if Your Lenses Aren't Perfect
      Lens Options
      • Single vision
      • Progressive
      • Non-polarized
      • Polarized
      • Reading
      • Bifocal
      Knox Size Narrow
      product spec click Lens Width 51 mm 2.01 inch
      product spec click Bridge 19 mm 0.75 inch
      product spec click Temple 149 mm 5.87 inch
      product spec click Width 127.2 mm 5.01 inch
      product spec click Lens Height 42.2 mm 1.66 inch
      Show in Inches Show in MM
      Size Width (mm)
      S (Narrow) 125-128mm
      M (Medium) 129-132mm
      L (Wide) 133-136mm
      XL (Extra Wide) 137-140mm

      We suggest you measure your frame dimensions to make sure your new glasses correctly fit your face.

      Knox

      Transparent Grey Square Eyeglasses
      £9.00
      SELECT LENSES
      Details & Size
      Description
      Shipping & Returns

      Product Details

      Sku: EM3851-04
      Rx Range: -20.00~+10.00
      PD Range: 58-78 mm

      *Additional cost for PDs outside this range

      Pupillary Distance (PD)       is the distance, in millimeters, between the centers of your pupils. It is required to position the optical center of your lenses for clear and accurate vision, especially for prescription and progressive lenses.

      Please note that the recommended PD range refers to Single PD, which is the total distance from one pupil to the other.

      If your prescription lists Dual PD (two numbers, e.g., 31/32), simply add them together to convert it to Single PD.

      Example:
      Dual PD: 31 / 32 → Single PD: 63 mm

      If you don’t know your PD, you can learn how to measure it here.
      Material: TR90
      Adjustable Nose: No
      Spring Hinge: No

      Frame Size

      Glass Size: Narrow

      S (Narrow):
      Frame Width 125-128mm
      M (Medium):
      Frame Width 129-132mm
      L (Wide):
      Frame Width 133-136mm
      XL (Extra Wide):
      Frame Width 137-140mm
      Frame Weight: 25.4 g

      All EYDOLOGY frame weights are measured without lenses or fillers, excluding non-prescription plano sunglasses frames.

      Ultra-Lightweight: Frame weight under 15g.
      Lightweight: Frame weight under 20g.

      Frame Width: 127.2 mm
      Bridge Width: 19 mm
      Lens Width: 51 mm
      Lens Height: 42.2 mm
      Temple Length: 149 mm

      Frame measurements

      Glass Frame Size IconGlass Temple Length Icon
      Show in inches
      127.2 mm
      51 mm
      42.2 mm
      19 mm
      149 mm

      With a cool translucent tone, the Knox transparent grey frame adds subtle depth to its sharp square design. The balanced proportions create a refined, contemporary look, making it a great choice for those who prefer understated style with a modern edge.

      Shipping

      Order Processing & Production: 3-5 business days (Complex lenses may take longer, such as photochromic lenses)

      Free Standard Shipping

      We're making shipping easier for you! Enjoy free standard shipping on product orders over $79.00 to the following countries: [USA].

      • Who Qualifies: Orders of $79.00 or more (before shipping fees).
      • Shipping Type: Standard shipping.
      • No Extra Steps: No coupon code needed, discount applies automatically at checkout.

      Shipping Time
      Standard Shipping: 7–19 days

      Visit our Shipping Policy page for more information.

      Returns

      We are committed to providing a positive shopping experience for our customers at Eydology. If you are not completely satisfied with your purchase, you may return:

      • For requests made within 30 days of receiving your order, you can choose between a refund to your original payment method or a store credit.
      • It is not possible to process a request for a credit/refund for non-quality issues if the request is made outside of this 30-day window.
      • Each order is eligible for a one-time exchange/return. Please kindly note that the "exchange order" is not eligible for another exchange/return.

      The original shipping fee of the order is non-refundable. Please ensure the items are in original condition, with the original case and tags. If there is a complimentary item in the order, it needs to be returned together.

      Visit our Returns Policy page for more information.

      • Our Packaging

        Our Packaging

        Every pair comes with a protective case, cleaning cloth, and detailed care guide to keep your glasses looking great.

      • Our Frames

        Our Frames

        Premium material offering rich colors and patterns. Lightweight and hypoallergenic. Perfect for all-day comfort and style.

      • Our Lenses

        Our Lenses

        We have a variety of lenses for you to choose from, and all lenses are high definition and will not affect your vision.

      Recently viewed

        Sign up for our newsletter

        Get $10 off your first order

        Join today and save $10 on your first order of $69+

        subscribe us banner