Choosing the Right Lens Refractive Index and Frames for High Myopia

For individuals with high myopia, selecting the right eyeglasses often presents a significant challenge. High prescriptions inevitably lead to thicker, heavier lenses, which can be cumbersome, aesthetically unappealing, and sometimes uncomfortable. The key question becomes: how can we achieve clear vision while keeping eyeglasses as light and attractive as possible? Today, we'll delve into the considerations for choosing lens refractive index and frames for high myopia, aiming to find the optimal balance.

1. High Refractive Index Lenses: The Trade-off Between Thinness and Aberration

To achieve thinner lenses for high myopia, high refractive index lenses are the answer. But what are their advantages and disadvantages?

Pros of High Refractive Index Lenses:

• Thinner: This is the most significant advantage. At the same prescription, lenses with a higher refractive index can be made thinner at the center. This allows individuals with high myopia to opt for thinner lenses, reducing the overall bulkiness of their eyeglasses.
• Lighter: Thinner lenses naturally mean reduced volume and weight. Wearing lighter eyeglasses greatly improves comfort and reduces pressure on the nose and ears.
• More Aesthetic: Thinner lens edges make eyeglasses look more attractive. High refractive index lenses prevent the "coke bottle" effect, boosting the wearer's confidence.

Cons of High Refractive Index Lenses:

• Lower Abbe Number: The Abbe number measures lens dispersion. Generally, lenses with a higher refractive index have a lower Abbe number, potentially leading to more noticeable chromatic aberration (color dispersion), especially with 1.74 high index lenses. Some may perceive rainbow-like fringes at the edges. However, advancements in technology mean some high refractive index lenses from reputable brands are designed and made with materials to minimize chromatic aberration.
• Higher Price: High refractive index lenses, especially ultra-high index options like 1.70 and 1.74, involve more complex manufacturing processes and higher material costs, making them more expensive.

2. Astigmatism and Axis: Unveiling the Secret of Lens Thickness Distribution

Besides myopia prescription, astigmatism is another crucial factor affecting lens thickness distribution. The Cylinder (CYL) and Axis in your eyeglass prescription reveal the secret behind lens thickness distribution.

Understanding Astigmatism (Cylinder) and Axis:

In simple terms, astigmatism means the eye has different focusing power in different meridians. Cylinder (CYL) indicates the degree of astigmatism, and Axis specifies the orientation of the astigmatism. In prescriptions, astigmatism is usually represented with a negative number, e.g., -1.00DC, and the axis is in degrees, e.g., 180°.

Impact of Astigmatism Axis on Lens Thickness:

For myopic lenses with astigmatism, the lens thickness varies across different orientations. The astigmatism axis influences how thickness is distributed across the lens, particularly for those with high myopia and astigmatism, where edge thickness can be even more uneven. During lens crafting, lenses are specially ground according to the astigmatism axis to correct astigmatism.

3. Thick Lens Edges? Frames to the Rescue!

Since myopic lenses are concave, the edges are naturally thicker than the center. Besides high refractive index lenses, we can also use frames to "hide" lens thickness.

The Principle of Concave Lenses Having Thicker Edges:

Myopic lenses are concave lenses, thin at the center and thick at the edges. Light passing through a concave lens diverges, focusing light onto the retina to correct nearsightedness. This diverging effect necessitates thicker edges.

Advantages of Small Frame Eyeglasses:

• Reduced Lens Area: Choosing smaller frames means smaller lenses. At the same prescription, smaller lenses require less material, naturally making them lighter.
• Less Protruding Edges: Small frames effectively control how much lens edges protrude. Thinner lens edges, even if slightly thick, are less likely to extend beyond the frame, enhancing the overall look of the eyeglasses.

*You can use the funnel filter function on the left to select the small-sized glasses frames that suit you (on the PC side). Currently, CC-Shield has more than 500 styles of glasses frames for you to choose from, and there will be more in the near future.

4. Thick Frame Eyeglasses: A Stylish Choice to Conceal Thick Edges

Besides small frames, trendy thick frame eyeglasses are also a boon for individuals with high myopia.

Advantages of Thick Frame Eyeglasses:

• Concealing Lens Edges: The biggest advantage of thick frames is their ability to cleverly hide lens edges. The wide, bold frames act like a "wall," effectively encasing thicker lens edges as much as possible, visually minimizing lens bulk and making eyeglasses appear more harmonious and attractive.
• Diverse Styles: Thick frame eyeglasses offer more design flexibility and come in a wider variety of styles. Whether you prefer a retro, literary, or trendy look, thick frames can handle it all. People with high myopia can choose thick frames that suit their face shape and style, making eyeglasses not just a vision correction tool but also a fashionable item that enhances personal charm.
• Fashionable and Retro: Thick frames themselves are a fashion trend. Many fashion brands have launched thick frame eyeglasses. Wearing thick frames can not only modify face shape but also add a retro and stylish touch to your overall look.

5. Frames and Lenses: An Economical Path to Balance

Opting for 1.74 or even higher refractive index lenses can certainly make eyeglasses extremely thin and light. However, ultra-high index lenses often come with a hefty price tag. For those prioritizing cost-effectiveness, using frames to modify lens thickness is undoubtedly a more economical choice.

Comparing High-Priced Lenses with Frame Modification:

The price of 1.74 refractive index lenses is typically several times higher, or even more, than standard lenses. Choosing suitable frames, such as small or thick frames, can achieve a similar effect of minimizing lens thickness at a lower cost.

Personalized Balance Solutions:

Everyone's myopia prescription, astigmatism, budget, and aesthetic preferences for eyeglasses vary. Therefore, the key to choosing lens refractive index and frames is finding a balance that suits you best. If you have high myopia and high demands for thinness and aesthetics, and have a sufficient budget, high refractive index lenses are undoubtedly the first choice. If you are more concerned about cost-effectiveness, or prefer retro, stylish thick frame eyeglasses, then choosing mid-index lenses (like 1.60, 1.67) paired with appropriate frames is also an excellent option.

Conclusion: Finding Your “Light,” “Thin,” and “Beautiful” Eyeglasses

Choosing eyeglasses for high myopia is never a simple, single-choice question, but a balancing act that requires comprehensive consideration. Lens refractive index, frame style, personal budget, aesthetic preferences… every factor is crucial. We hope this blog post helps you better understand the key considerations for choosing high refractive index lenses and frames. Find the best “light,” “thin,” and “beautiful” eyeglass solution for yourself, making eyeglasses your powerful assistant for seeing the world clearly and a fashionable partner that showcases your personality and taste.

CC-Shield has summarized some glasses frames suitable for thick lenses for you, suitable for all face shapes (click to view).