Spherical or aspherical denotes the profile of a lens. Spheric lenses use a single curve in their profile, whilst aspheric lenses use varying curves. These varying curves make your lenses thinner and generally flatter which makes them look nicer and prevents your eyes being magnified.
What is an aspheric lens profile?
Aspheric Lenses And Slimmer Profiles. Most aspheric lenses also are high-index lenses. The combination of an aspheric design with high-index lens materials creates a lens that is noticeably slimmer, thinner and lighter than conventional glass or plastic lenses.
What are aspheric eyeglasses?
Advanced optical design technology allows aspheric eyeglass lenses to be made with flatter curves than conventional lenses, giving them a slimmer, more attractive profile. Conventional lenses have a front surface that is spherical, meaning it has the same curve across its entire surface, much like a baseball.
What is the difference between aspheric and spherical lenses?
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.
Are progressive lenses aspherical in design?
Yes, progressive lenses are aspherical in design. The curvature of these lenses gradually changes from the top to the bottom. Why are aspheric lenses expensive? Aspherical lenses are expensive due to manufacturing costs.
Are aspheric lenses better?
Whether you are nearsighted or farsighted, aspheric lenses are thinner and lighter and have a slimmer profile than ordinary lenses. Aspheric lenses have a slimmer profile for virtually all prescriptions, but the difference is especially dramatic in lenses that correct high amounts of farsightedness.
What does SV mean on lenses?
Today's profit-hungry marketplace views basic standard plastic single vision (SV) lenses as a commodity product, as they offer little profit margin.
What does an aspheric lens do?
Aspheric lenses allow optical designers to correct aberrations using fewer elements than conventional spherical optics because the former gives them more aberration correction than multiple surfaces of the latter.
Why are aspherical lenses better?
An aspheric lens is designed with less curvature than its traditional counterpart. Think: flatter and thinner. In both farsighted and nearsighted prescriptions, aspheric lenses provide a slimmer profile and minimize eye distortion without compromising optical quality.
What type of lens is SV?
Single vision glasses are designed to help people who require correction of farsightedness, nearsightedness, or astigmatism. These eyeglasses have just a single optical prescription correction and they distribute focus evenly over the entire surface area of the lens. Most people that wear glasses usually get this type.
What is free form SV lenses?
Free-form lens design may be categorized into three basic types: Optimized free-form designs overcome optical aberrations and mechanical limitations of traditional surfacing. All lenses designed with digital free-form technology are effectively “optimized” because they can be precisely generated to a power of 0.01D.
Who benefits from aspheric lenses?
People who have higher order refractive errors, usually +4.00 diopters or more, benefit the most from aspherical lenses. Reading glasses and contact lenses are also being manufactured with this type of lens, so more people can benefit from clearer vision.
What is the difference between aspheric and spherical lenses?
Spherical or aspherical denotes the profile of a lens. Spheric lenses use a single curve in their profile, whilst aspheric lenses use varying curves. These varying curves make your lenses thinner and generally flatter which makes them look nicer and prevents your eyes being magnified. Combining high index & aspheric.
Are aspheric lenses good for astigmatism?
Aspheric lenses can correct low astigmatism up to –0.75, or presbyopia. BUT: There are individuals who do not benefit from the aspheric lens surface. Their eyes depend on spherical aberrations to ensure optimal vision.
Are all progressive lenses aspheric?
In reality, progressive lenses are neither a type of bifocal or trifocal - they are "aspheric" in design, which means the curvature (and focusing power) gradually changes from the top of the lens to the bottom.
Are all high index lenses aspheric?
To make high index lenses even more attractive, most of them have an “aspheric” design. This means that, instead of having a round (or “spherical”) curve on the front surface, these lenses have a curve that gradually changes from the center of the lens to the periphery.
What is the ideal lens shape?
It is only somewhat well known that a hyperboloid is the ideal lens shape for this purpose when using media with a relative refractive index greater than one. Less well known, is the fact that an ellipsoid is the ideal shape for a lens com- posed of media with relative index between zero and one [1].
Aspheric Lenses and Slimmer Profiles
Most aspheric lenses also are high-index lenses. The combination of an aspheric design with high-index lens materials creates a lens that is notice...
Superior Optics With Aspheric Lenses
With conventional lens designs, some distortion is created when you look away from the center of the lens — whether your gaze is directed to the le...
A More Natural View of The World — and Your Eyes
Because aspheric lenses have flatter curves than conventional lenses, they fit closer to your face. This is a major benefit for anyone wearing a st...
Buying Eyeglasses With Aspheric Lenses
Aspheric designs are available in single vision lenses for the correction of nearsightedness, farsightedness and astigmatism, and in progressive le...
What is an aspheric lens?
Most aspheric lenses also are high-index lenses. The combination of an aspheric design with high-index lens materials creates a lens that is noticeably slimmer, thinner and lighter than conventional glass or plastic lenses.
What is the difference between a spherical lens and an aspheric lens?
Aspheric lenses, on the other hand, have a more complex front surface that gradually changes in curvature from the center of the lens out to the edge.
What is a convex lens?
Lenses that correct farsightedness (convex or "plus" lenses) are thicker in the center and thinner at their edge. The stronger the prescription, the more the center of the lens bulges forward from the frame. Aspheric plus lenses can be made with much flatter curves, so there is less bulging of the lens from the frame.
Why are aspheric lenses better than conventional lenses?
A More Natural View Of The World — And Your Eyes. Because aspheric lenses have flatter curves than conventional lenses, they fit closer to your face. This is a major benefit for anyone wearing a strong correction. Conventional spherical lenses with a strong prescription for farsightedness cause unwanted magnification.
What is distortion in a lens?
With conventional lens designs, some distortion is created when you look away from the center of the lens — whether your gaze is directed to the left or right, above or below.
Do aspheric lenses reflect?
Since aspheric lenses are flatter and positioned slightly closer to the face than conventional lenses, some wearers may notice more reflections off the front and back surfaces of the lenses. For this reason, anti-reflective coating is highly recommended for all aspheric lenses.
Do conventional lenses for farsightedness make things smaller?
And because this magnifying effect goes both ways, conventional lenses for farsightedness also give the wearer's eyes an unnaturally magnified, "bug-eyed" look. Conventional lenses for nearsightedness do just the opposite: They make things look smaller and give the wearer's eyes a small, "beady-eyed" appearance.
Why are aspheric lenses important?
While aspheric lenses are a great option for many people who wear glasses, it is important to make sure the center of the lens lines up with your pupil. Particularly with this type of lens, your vision can become distorted if the pupillary distance is off-center.
Why are aspheric lenses better than other lenses?
Benefits of aspheric lenses include: A sleeker profile to your glasses. A lightweight material so your nose bridge has less pressure. More frame options for people with higher prescriptions because the lenses are not as large.
What is an IOL lens?
Aspheric Intraocular Lenses (IOLs) If you have cataracts that obscure your vision, you are likely to be recommended for cataract surgery. This process removes the natural lens of your eye and replaces it with an artificial lens, called an intraocular lens (IOL).
How much diopters are needed for aspheric lenses?
Anyone with a higher order refractive error can benefit from aspheric lenses. This is typically around +4.00 diopters or higher. Traditional glasses become bulky and heavy because they must be thick enough to correct curvature problems in your cornea or lens.
What type of lenses are used for cataract surgery?
( Learn More) Aspherical intraocular lenses (IOLs), which are implanted during cataract removal surgery, are also being recommended to manage refractive errors. ( Learn More)
Why are myopia glasses concave?
When lenses treat higher order vision problems, traditional lenses are thicker in some areas , which creates the “coke bottle lens” effect. Many people find this unattractive and avoid wearing their glasses as a result.
What happens when light rays move from the center of the lens to the edges?
Distortion. This is when light rays move from the center of the lens to the edges, increasing magnification.
The evolution of the traditional single vision lens
Hoya Vision Aspheric Single Vision lenses are designed to provide crisper, clearer viewing zones than standard single vision lenses.
What is this product called in my region?
As a global company, our product range and product names may differ locally.
What is Essilor lens?
Essilor. Essilor is the world leader in corrective lenses. Its international presence and ability to meet local specificities enables the brand to adapt to the needs of consumers across the world.
What is single focus lens?
Nearsightedness, farsightedness or astigmatism: the single vision or ‘single focus’ lens is the most obvious solution to fix simple visual defects. Its characteristic: it has the same power over the whole of its surface. It can come in two forms: one with a spherical surface for moderate vision corrections or an aspherical surface ...
