Materials for Ophthalmic Lenses: Pros and Cons

Ophthalmic lenses come in a variety of materials, each with its unique properties, advantages, and disadvantages. Choosing the right lens material is crucial to ensure optimal vision and comfort.

When deciding on a prescription lens material, there are several factors to consider, such as the strength of the prescription, the purpose of the lenses, and the type of frames used. For instance, lenses for regular use and lenses for sports may require different materials due to differences in durability and impact resistance. Lenses for children and lenses for rimless-frames may need to be more impact-resistant. One more important factor to consider is the Abbe value, which measures the amount of chromatic aberration in a lens. In this article, we will discuss the various materials available for ophthalmic lenses, including plastic or CR-39, 1.59 index polycarbonate, 1.53 trivex, 1.60 MR, 1.60 Tribrid, high-index materials such as 1.60, 1.67, and 1.74, and glass lenses, along with their Abbe value, to help you make an informed decision.

CR-39 or Standard Plastic Lenses

Refractive Index: 1.49 | Abbe value : 58

CR-39 or standard plastic lenses are the most common and affordable option. They are made of a lightweight and durable plastic material called CR-39. These lenses are suitable for low to medium prescriptions and come in different thicknesses. They are moderately impact-resistant and shatter-resistant, and are ideal to fit in full-metal or full-plastic frames. However, they tend to be thicker than other materials because of the low refractive index and may not be suitable for individuals with strong prescriptions.

One advantage of CR-39 or standard plastic lenses is that they have an Abbe value of 58, which is very close to the Abbe value of glass lenses at 59. This means the optical quality of CR39 is very close to glass-lenses

Pros: Affordable, lightweight, suitable for low to medium prescriptions, .

Cons: Tend to be thicker than other materials, not suitable for individuals with strong prescriptions.

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Trivex Lenses

Refractive Index: 1.53 | Abbe value : 58

Trivex lenses are a newer material that is similar to polycarbonate but provides better optics. Trivex lenses are highly impact-resistant and lightweight, making them a good choice for sports or other high-impact activities.. These lenses have a higher Abbe value than polycarbonate lenses, meaning they are less prone to chromatic aberration. Chromatic aberration is a visual distortion that can occur when light passes through a lens, causing colors to separate and blur. Trivex lenses are an ideal choice for people with moderate prescriptions who want the best optics possible.

Pros: Lightweight, impact-resistant, excellent clarity, higher Abbe value than polycarbonate lenses.

Cons: More expensive than standard plastic lenses, With it’s relatively low refractive index (1.53) – not an ideal choice for prescriptions above +/-3.00 D

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1.59 Index Polycarbonate Lenses

Refractive Index: 1.59 | Abbe value : 30

1.59 index polycarbonate lenses are thinner and lighter than standard plastic lenses. They are made of a durable plastic material that is highly impact-resistant, making them an ideal choice for sports and safety glasses. These lenses provide 100% UV protection, making them a great choice for people who spend a lot of time outdoors. However, their scratch-resistance can be lower than some other lens materials, and their optical clarity may not be the best.

Pros: Thinner and lighter than standard plastic lenses, highly impact-resistant, provide 100% UV protection.Inexpensive compared to other impact resistant materials

Cons: Lower scratch-resistance than some other lens materials, optical clarity may not be the best.

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1.60 Index MR8 Lens Material

Refractive Index: 1.60 | Abbe value : 40

MR 8, created by Mitsui Chemicals provide optical lenses with a high refractive index, high Abbe numbers, low specific gravity and high impact resistance. These lenses are thinner and lighter than standard plastic lenses-thanks for the 1.60 refractive index- and are suitable for moderate prescriptions. They provide good optical clarity, and their scratch-resistance is better than plastic lenses.

Pros: Thinner and lighter than standard plastic lenses, highly impact-resistant, provide 100% UV protection.

Cons: Slightly more expensive than Polycarbonate

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1.60 Index Tribrid

Refractive Index: 1.60 | Abbe value : 41

Tribrid lens material was introduced in 2012 as a high index extension of the Trivex family to address patient needs for thinner lenses. It combines the best lens properties of high-index and Trivex to provide patients with enhanced all-around performance for stronger prescription requirements. The material offers excellent optical quality (ABBE 41), lightweight (1.23 g/cm specific gravity), thinness (1.60 index of refraction) and strength (up to 5X more impact resistant than other high index lens materials -making it an ideal choice for kids glasses with stronger prescription, sports glasses and rimless frames.

Pros: High abbe value , provides better Optical clarity than Polycarbonate, highly impact-resistant, provide 100% UV protection.

Cons: Slightly more expensive than Polycarbonate

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High-Index Plastic Lenses – 1.60, 1.67 & 1.74

High-index lenses come in different refractive indices, including 1.60, 1.67, and 1.74. The higher the refractive index, the thinner and lighter the lens. High-index lenses are suitable for individuals with strong prescriptions who want a thinner and lighter lens than standard plastic lenses.

Pros: Thinner lenses, ideal for strong prescriptions

Cons: More expensive than materials of lower refractive index

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Glass Lenses

Glass lenses were once the most common material used in eyeglasses. However, due to their weight and tendency to break easily, glass lenses are seldom used. But it’s still a good option for people with very strong prescriptions ( above +/-10.00 D , for example ) because of the fact that glass lenses are available up to 1.90 Index ( compared to the 1.74 in plastic lenses) – so that the lenses can be made much thinner than plastic lenses.

Pros: Highest optical quality with Abbe value 59, Available up to 1.9 index

Cons: Heavy, High risk of breakage; Higher index glasses are more expensive