What are Aspheric Lenses?

What Are Aspheric Lenses & How Do They Work?

Aspheric lenses are flatter than conventional lenses, but they still offer the same vision-enhancing benefits. They have a more attractive profile because there is less curvature. This means they don’t have the same “coke bottle” look as you get with traditional lenses. 

Aspheric lenses have a more complex front surface with a gradual curve. They also perform better by improving the way light refracts onto the retina.

Most aspherical lenses are high-index, which, when combined with the aspheric design, offers a slimmer and lighter option for people who wear glasses. This improves the look and feel. 

Glasses wearers who have mild prescriptions may not notice a big difference. Those with a strong prescription for farsightedness (who usually wear thicker glasses) will experience a significant change.

Reducing the thickness of the lens offers other benefits. Slimmer lenses give you more options when it comes to choosing frames. Thick lenses limit your options, which means people with a strong prescription often have to settle for unstylish frames. This is no longer the case with aspheric lenses.

What Vision Problems Can Aspheres Correct?

Aspheric lenses work for people who struggle with: 

• Farsightedness. The difference between conventional and aspheric lenses is more noticeable for those who are farsighted, but these lenses correct both near and far vision deficiencies.
• Nearsightedness (myopia). This means someone sees objects close to them clearly, but objects farther away are blurry. It happens because the shape of the eye bends light rays improperly. This means images are focused in front of your retina instead of on your retina.
• Astigmatism. The complex aspheric surface of these lenses can eliminate or greatly reduce spherical aberration and optical aberrations (like astigmatism), compared to a spherical eyeglass lens. 
• Presbyopia. When a person has age-related farsightedness (presbyopia), it means they can see distant objects clearly, but objects nearby are blurred. The degree of farsightedness affects your focusing ability. In severe cases of farsightedness, people also see blurry at a distance. Milder cases usually mean closer objects are somewhat clear, but there’s still blurring. It’s more common to develop farsightedness as you age, but anyone can experience this issue.

Farsighted lenses are thick at the center and thin out gradually toward the edges. Stronger prescriptions require thicker lenses, which means some conventional lenses used to correct drastic cases of farsightedness have very thick bulges at their center. Aspheric lenses reduce this thickness, so lenses have a slimmer, flatter profile.

Nearsighted lenses are the opposite of farsighted lenses. They are thicker at the edges and thinner at the center. This alleviates the bottled look but means the person’s eyes look smaller. For some, this distortion causes a beady-eyed look they don’t like. Aspheric lenses correct this problem and give a more natural appearance to the wearer’s eyes.

Aspheric lenses come in single vision or progressive lenses, bifocals, and trifocals. These lenses also have more reflections, so your eye doctor may recommend an anti-reflective coating. 

Conventional Spherical Lenses

For most people, aspheric lenses are an upgrade from their conventional lenses. But how significant an upgrade depends on the prescription strength.

Conventional lenses have a spherical design and create unwanted magnification. This means people with farsightedness see objects larger and closer than they are in reality. Their eyes are also magnified by their lenses, which means they might have a bug-eyed look when wearing their glasses.

Those who wear conventional lenses for nearsightedness experience the opposite. Objects look smaller and their eyes appear smaller or “beady.” Aspheric lenses correct these problems while improving vision just the same as conventional lenses. They look more natural and are more comfortable to wear.

Aspheric Lenses vs. Conventional Spherical Lenses

The primary difference between conventional and aspheric lenses are their spherical surfaces. Aspheric means “non-spherical,” so there is less of a bulge or curve. Conventional lenses have a spherical curvature on the front of the lens (like a basketball), which increases the size and weight when a prescription is strong.

Aspheric lenses are smoother and flatter, reducing the distortion that occurs when someone wears glasses. For many people, this improvement means feeling better in their glasses and being more willing to wear their corrective lenses. Aspheric lens elements are also more complex than spherical lenses.

In the past, the only option someone would have if they did not like how they looked in conventional lenses was to wear contacts, undergo a corrective laser vision procedure, or avoid wearing their glasses. This is no longer the case with aspheric lenses.

Conventional lenses are prone to spherical errors (aberrations) that create blurry images. Even slight blurring makes wearing glasses uncomfortable. Aspheric lenses do not have this problem.

Benefits of Aspheric Eyeglass Lenses

Aspheric lenses aren’t just about style. Many people choose them because they like how they look in them more than they do in conventional glasses. Many wearers also like that they can choose the frames that best suit their face when upgrading to aspherics.

But style isn’t the only reason people choose this type of lens. Aspheric lenses offer many benefits, including:

• Spherical aberration correction (makes corrected image less blurry)
• Improved performance
• Slimmer and thinner profile
• More frame options, even for people with strong prescriptions
• Improved image quality
• Sleeker profile
• Lightweight and more comfortable
• More natural appearance
• Improved peripheral vision
• Multiple lens designs to choose from