Tintable Hard Coat

2. The Tinting Process

The process is relatively simple and is done using a specialized dye bath machine:

1. Color Selection: The desired color is chosen from a swatch book or digital display. The lab technician selects the corresponding dye pellet or liquid.

2. Heating the Dye: The dye is mixed into a small tank of water and heated to a specific temperature (usually near boiling). The heat opens the microscopic pores in the lens coating.

3. Immersion: The clear, hard-coated lenses are immersed in the hot dye bath.

4. Timing: The longer the lenses stay in the bath, the darker the tint becomes. The technician monitors this closely to achieve the exact shade requested (e.g., Light, Medium, Dark).

5. Rinsing and Cooling: Once the desired shade is reached, the lenses are removed, rinsed, and cooled. The cooling process closes the pores in the coating, locking the dye permanently inside the lens.

6. Final Coating (Often): After tinting, an anti-reflective (AR) coating is almost always applied on top. This is because the tint can create more internal reflections, and the AR coating eliminates this, improving clarity and aesthetics. The AR coating is applied after the tinting process.

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3. Available Colors & Their Uses

Tintable hardcoat lenses offer a vast spectrum of colors, from fashion-focused to functional.

Solid Colors (Most Common):

• Brown / Grey / Green: The classic sunglass colors. Grey provides true color perception, brown enhances contrast, and green is a popular all-purpose choice.

• Blue / Purple / Pink / Red / Yellow / Orange: These are popular for fashion statements, sports performance, or brand colors (e.g., purple for a Lakers fan).

• Amber: A specific color that is excellent for enhancing contrast in variable light conditions, popular among golfers and pilots.

Gradient Tints:

• The lens is dipped for only part of the time, creating a fade from dark at the top to light at the bottom. A classic “aviator” style look that is good for driving (dark top shields from sun, light bottom lets you see the dashboard).

Double Gradient Tints:

• The lens is dipped from both the top and bottom, leaving the center horizontal band clear. A very stylish, modern look.

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4. Key Advantages

• Customization: The #1 advantage. You can match any frame color, team colors, or personal style exactly.

• Cost-Effective: It’s often cheaper to tint a clear lens than to order a pre-tinted prescription sunglass lens.

• Versatility: A single pair of glasses can be re-tinted multiple times if you want to change your look (though this is not common in practice, it is possible).

• Availability: Most optical labs can do this quickly, often while you wait.

5. Important Limitations & Considerations

• Not for Extreme Darkness: For very dark sunglasses (e.g., for intense beach or snow glare), pre-tinted lenses are better. They are made from a material that is dark all the way through, whereas tinted hardcoats are a surface dye. Pre-tinted lenses often offer superior sun protection.

• Photochromic Lenses are Different: Lenses that darken automatically (like Transitions®) are a different technology. You cannot tint a photochromic lens, and you cannot make a tintable hardcoat lens photochromic.

• Impact on Coatings: You cannot tint a lens that already has an Anti-Reflective (AR) coating. The AR coating is a sealed, non-porous layer that will not accept dye. The tint must always be done before the AR coat is applied.

• Polarization: Tinting does not add polarization. Polarization is a separate filter laminated inside the lens to block blinding horizontal glare. If you want a polarized sunglass, you must order a lens that is manufactured as polarized from the beginning. You cannot “add” polarization by tinting.

• Material Matters: Some lens materials (like Polycarbonate) tint lighter and faster than others (like CR-39). A good lab technician will know the correct timing for each material.

Summary: Who are they for?

Tintable hardcoat lenses are an excellent choice for:

• Fashion-conscious individuals who want to perfectly match their glasses to their outfit or frame.

• Everyday sunwear for driving and urban use.

• People who want a second pair of prescription sunglasses without a high cost.

• Specialty applications like sports tints (yellow for contrast, light rose for overcast days).

For extreme outdoor sports, driving, or high-glare environments, a dedicated pre-tinted, polarized sunglass lens is usually the superior performance choice.