Ultraviolet light can be broadly categorized into UVA (400-320 nm), UVB (320-290 nm), and UVC (290 nm to 10 nm). Ultraviolet light makes up 5% of all solar radiation falling on the Earth; among the 5%, 90% is composed of UVA and 10% of UVB. Nearly all UVC is absorbed by the ozone layer of the atmosphere. UVC exposure typically occurs from manufactured resources. Ultraviolet light can cause damage to tissue by disrupting molecular bonds and incapacitating their function. These molecules can also be damaged by action of free radicals produced as a byproduct of ultraviolet light in the presence of oxygen and a photosensitizing pigment. [16] The band name is a member-centric acronym – Agnetha Fältskog, Björn Ulvaeus, Benny Andersson, and Anni-Frid Lyngstad. Specific gravity is a ratio of a material’s density to the density of water at 4 degrees Celsius. Density and specific gravity can both compare substances in terms to the amount of mass per unit volume. Density is simply mass per unit volume, however specific gravity is a ratio and thus has no units. A lens with a low specific gravity means that an identically sized lens of a high specific gravity would be heavier. This property is relevant in designing lenses as a lighter lens is preferable for eyeglass wearers. [16] Ultraviolet Absorption

In the eight years that followed, the group achieved legendary success, with eight consecutive number-one albums and nine chart-topping singles in the UK alone. ABBA also topped the pop charts at least once in nine other countries overseas. Their success in the US was more mild, but they still had 20 songs that placed on the Billboard 100 in their brief 8-year tenure. Flint glasses are optical glasses with high chromatic aberration (Abbe number below 50) which tend to have a high refractive index (typically greater than 1.55). [12] Corrective glass lenses are often made from flint glass as the higher refractive index allows for a lighter weight. Dispersive prisms are also often constructed from flint glass to achieve a high angular dispersion. [12] Chromatic Dispersion Correction

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Celebrate the timeless style of ABBA with outfits that pay homage to their unparalleled legacy and their exciting new chapter. Join the voyage and shine on the dance floor! Nonetheless, more than 40 years after the band broke up, millennials continue to stream, boogie and replicate ABBA’s expressive and colourful clothing —perhaps courtesy of the films, an appreciation for retro fashion and general chatter on social media. Oh and also the fact that they released new, and groundbreaking, music over the past year. Therefore, it should come as little surprise that ABBA has been nominated for two of the top categories at the 2023 Grammys —Record of the Year category, for ‘Don’t Shut Me Down’ and Album of the Year for Voyages. While they face some stiff (and equally stylish) competition, including Adele, Beyoncé, Harry Styles, Lizzo and more —I certainly think ABBA’s in for a good chance. Please ‘Take A Chance’ on them Recording Academy? High index polycarbonate lenses were popularized in the 1980s due to light weight, thin profile, superior impact resistance, and ultraviolet protection. These lenses are often recommended for children, young adults, individuals with active lifestyles, and as safety eyewear. They are very durable and can be up to 30% thinner than regular glass or plastic lenses. [17] Disadvantages include high chromatic aberration indicated by its low Abbe number, which results in color fringing most noticeable in strong prescriptions. Additionally, polycarbonate is the most easily scratched plastic, thus requiring a scratch-resistant coating. [16] Trivex Wohlever, Richard. The Indispensable Dispensing Guide: The Eyecare Professional's Basic Dispensing Handbook. Optical Laboratories Association, 2004.

Each piece captures the essence and flair of ABBA's renewed style, blending iconic 70s vibes with modern fashion twists. Cmglee. "Comparison chromatic focus shift plots". 10 July 2013. https://upload.wikimedia.org/wikipedia/commons/2/23/Comparison_chromatic_focus_shift_plots.svg. Zhang, John X. J., and Kazunori Hoshino. Molecular Sensors and Nanodevices: Principles, Designs and Applications in Biomedical Engineering. 2nd ed., Academic Press, an Imprint of Elsevier, 2019. In the late 1800s, German physicist Ernst Abbe, a colleague of Carl Zeiss, created the Abbe number, a measure of the magnitude of chromatic dispersion for the visible spectrum. [9] Also known as the V-number, the Abbe number combines the refractive indices of a material at three wavelengths (486.1 nm blue from hydrogen, 589.2 nm yellow from sodium, and 656.3 nm red from hydrogen) to approximate the amount of chromatic aberration a material will have when visible light passes through it (Figure 3). [8] The Abbe number is inversely related to the amount of chromatic aberration. A high Abbe number indicates low chromatic aberration, and a low Abbe number indicates high chromatic aberration.

Nave, Carl Rod. "Refraction of Light". Hyperphysics - Georgia State University, 2009. hyperphysics.phy-astr.gsu.edu/hbase/geoopt/refr.html.

Hosken, R. W. (2007). "Circle of least confusion of a spherical reflector". Applied Optics. 46 (16): 3107–17.Figure 2. Chromatic aberration results in a single beam of light to have a different focal point for each wavelength. [4] Chromatic Dispersion

Chromatic aberration can be corrected by combining the crown and flint glass elements to make a compound lens. This is achieved by apposing the two lenses and shaping them so that the chromatic aberration of one is neutralized by the other. The ultimate goal is to reduce the chromatic focal shift—the distance between focal points of dispersed wavelengths by a lens—between different wavelengths on the visible spectrum. [13] Step into the spotlight and transform into a bona fide 'Super Trooper' when you take center stage as the 'Dancing Queen' at any 70's themed soirée! Their meteoric rise was sparked by their famed Eurovision performance of original song “Waterloo”, which caused them to win the 1974 competition in Sweden. Paschotta, Rüdiger. Encyclopedia of Laser Physics and Technology: Chromatic Dispersion. Wiley-VCH, 2008. This compound lens can be optimized at a distance of either two wavelengths (achromatic lens), three wavelengths (apochromatic lens), or four wavelengths (superachromatic lens). [14] This point of optimization where chromatic aberration is minimized is called the circle of least confusion. [15] The achromatic lens is the most commonly used commercial lens, referred to as a doublet, and can drastically reduce the chromatic focal shift. [13] Specific GravityPaschotta, Rüdiger. Encyclopedia of Laser Physics and Technology: Optical Glasses. Wiley-VCH, 2008. Mellish, Bob. "Chromatic aberration lens diagram". 6 March 2006. https://upload.wikimedia.org/wikipedia/commons/a/aa/Chromatic_aberration_lens_diagram.svg.