{"id":8967,"date":"2020-11-25T20:29:48","date_gmt":"2020-11-25T20:29:48","guid":{"rendered":"https:\/\/www.optometrists.org\/?page_id=8967"},"modified":"2021-08-02T08:37:51","modified_gmt":"2021-08-02T08:37:51","slug":"guide-to-high-index-lenses","status":"publish","type":"page","link":"https:\/\/www.optometrists.org\/general-practice-optometry\/optical\/guide-to-optical-lenses\/guide-to-high-index-lenses\/","title":{"rendered":"Guide to High-Index Lenses"},"content":{"rendered":"

What are high-index lenses?<\/b><\/h2>\n

High-index lenses are eyeglass lenses that are designed to be thinner and lighter than regular lenses. They are generally recommended for people who have significantly high refractive errors and strong prescriptions for nearsightedness<\/a>, farsightedness<\/a>, or astigmatism<\/a>.<\/p>\n

Regular lenses that contain a strong optical prescription usually require a thicker and heavier lens in order to bend light more effectively and correct the high refractive error.<\/p>\n

While both regular and high index lenses function in the same way,<\/b> high index lenses are designed to bend light <\/b>more efficiently<\/i><\/b> \u2014 leading to thinner and lighter lenses.<\/b><\/p>\n

Schedule an appointment<\/strong><\/a> with an eye doctor to find out if high-index lenses are a good fit.<\/p>\n

What is a refractive index?<\/b><\/h2>\n

The refractive index is the number that represents how efficiently a lens material bends light, and is dependent on how quickly light travels through the material.\u00a0<\/b><\/p>\n

Regular plastic lenses<\/b> have a refractive index of 1.50.<\/b><\/p>\n

This index is adequate for correcting mild to moderate refractive errors, but is not as effective for the correction of higher refractive errors.<\/p>\n

A high-index lens may be recommended if your optical prescription is above 2.00 diopters.<\/p>\n

High-index lenses<\/b> have a refractive index above 1.50\u2014 ranging from 1.53 to 1.74.\u00a0<\/b><\/p>\n

The image below compares the lens thickness of a regular plastic lens (1.50) to the most commonly prescribed high-index lenses.\u00a0<\/i><\/p>\n

\"\"<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 Note: The higher the refractive index, the thinner the lens.<\/p>\n

According to this table, a lens with an index of 1.74 could be up to 50 percent thinner than a regular plastic lens with an index of 1.50, with the same optical prescription.<\/b><\/p>\n

Polycarbonate lenses have a refractive index of 1.59.<\/b><\/p>\n

Polycarbonate lenses are impact resistant and offer increased durability, but are generally only recommended for children\u2019s glasses, sports eyewear and safety goggles because they don\u2019t provide the same level of visual clarity, when compared to other plastic lenses.<\/p>\n

If you need high-index lenses contact an eye doctor near you<\/strong><\/a> to start improving your vision.<\/p>\n

SEE RELATED:<\/strong> Glass or Plastic: Which Type of Lens Should You Choose?<\/a><\/p>\n\n\t

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