What are High-Index Lenses? Advantages, Disadvantages & Recommendations
Explaining high-index lenses: lightweight lenses for high myopia. Listing refractive index, pros and cons, and how to choose suitable thin lenses.
Optometrist Vũ Văn Tiệp
November 5, 2025
What are High-Index Lenses? A Guide to Choosing
High-index lenses (thin lenses) are a solution for people with high myopia when regular lenses are too thick and heavy. With a high refractive index, thin lenses make glasses lighter and more aesthetically pleasing. The following article explains the pros and cons of thin lenses and how to choose the appropriate index.
What are High-Index Lenses?
High-index lenses (high refractive index lenses) are lenses with a refractive index higher than standard lenses. The higher the refractive index, the thinner and lighter the lens is at the same level of myopia.
What is the refractive index?
The refractive index measures the ability of a material to bend light. Regular lenses typically have a refractive index of 1.50 (CR-39) or 1.53 (Trivex). High-index lenses start from 1.56 and above:
| Index | Classification | Thickness reduction compared to 1.50 |
|---|---|---|
| 1.50 | Standard | — |
| 1.56 | Average | ~15-20% |
| 1.60 | High | ~25-30% |
| 1.67 | Very high | ~35-40% |
| 1.74 | Ultra high | ~45-50% |
The main target for high-index lenses is people with myopia from -4.00 and above or hyperopia from +3.00 and above. For low myopia (below -3.00), standard 1.50 lenses are already thin enough and do not require an upgrade.
Advantages of Thin Lenses
Lightweight
High-index lenses are thinner, so they are significantly lighter than regular lenses. For people with high myopia (over -6.00), the weight difference is very noticeable – glasses are more comfortable to wear, without causing pressure on the nose or headaches.
Improved Aesthetics
Thick myopic lenses with a low index will be very thick at the edges, creating an unappealing "bottle bottom" effect. High-index lenses significantly reduce edge thickness, making glasses look more elegant. This is especially important when using thin or rimless frames.
Reduced Distortion Effect
Thick lenses tend to magnify or shrink the eyes when others look at them (myopic eyes appear smaller, hyperopic eyes appear larger). High-index lenses reduce this effect, making the eyes look more natural.
Compatibility with Various Frame Styles
Thin lenses allow you to choose from a wider range of frame styles, including thin metal frames, semi-rimless frames, or rimless frames – styles that thick lenses cannot accommodate.
Disadvantages of Thin Lenses
Higher Cost
High-index lenses are 2-5 times more expensive than standard lenses:
| Index | Reference Price (VND) |
|---|---|
| 1.50 | 200,000 – 500,000 |
| 1.56 | 400,000 – 800,000 |
| 1.60 | 600,000 – 1,500,000 |
| 1.67 | 1,000,000 – 2,500,000 |
| 1.74 | 2,000,000 – 5,000,000 |
The prices above are for reference; depending on the brand and coating, the prices may be higher.
Susceptible to Aberration
High refractive index lenses tend to create chromatic aberration at the edges of the lens. This occurs because the material has a lower Abbe number – a higher dispersion of light. Therefore, high-index lenses require good anti-reflective coatings to compensate for this disadvantage.
More Reflective
The surface of high refractive index lenses reflects more than regular lenses if they do not have an AR (anti-reflective) coating. Thus, purchasing high-index lenses without an AR coating is a waste.
Not Necessary for Low Myopia
If you have myopia below -2.50, high-index lenses do not provide significant benefits in terms of thickness. The difference is too small to notice, while the cost increases significantly.
Guide to Choosing the Appropriate Refractive Index
Based on Myopia Level
- Myopia -1.00 to -2.50: Use 1.50 or 1.56 lenses. The lenses are already thin, no need to invest further.
- Myopia -2.50 to -5.00: Should use 1.60 or 1.67. In this range, the difference in thickness is noticeable.
- Myopia above -6.00: Should use 1.67 or 1.74. This group benefits the most from high-index lenses.
Based on Frame Style
- Thick plastic frames: The frame edges can cover the lens thickness, so a lower index can be used.
- Thin metal frames: Need thin lenses as the edges of the lenses are exposed.
- Rimless/semi-rimless frames: Should use the highest possible index as the lenses are fully exposed.
Expert Advice
- Always include a good AR coating: Essilor Crizal, Hoya Super Hi-Vision, or equivalent to reduce reflections and aberrations.
- Consult an expert: Each case is different, and experts will help you balance cost and effectiveness.
- Consider long-term costs: Good lenses can last 2-3 years, making the daily cost very small.
Comparison of Thin Lens Brands
| Brand | Featured Line | Characteristics |
|---|---|---|
| Essilor | Airwear (1.59), Thin&Lite (1.67/1.74) | Wide distribution, many coatings |
| Hoya | Hi-Vision (1.60/1.67/1.74) | Thinnest lenses, excellent AR |
| Zeiss | ClearView (1.60/1.67/1.74) | German quality, high price |
| Nikon | Lite AS (1.60/1.67) | Good aspheric technology |
Conclusion
High-index lenses are an excellent solution for people with high myopia, making glasses thinner, lighter, and more aesthetically pleasing. Choose the appropriate index based on your myopia level and frame style, always including quality AR coatings for the best experience.
Explore and try quality thin lenses from leading brands at Kính Mắt Điện Biên Phủ – 529 3/2 Street, Vườn Lài Ward, Ho Chi Minh City for the best solution for your eyes.
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