{"id":1580,"date":"2023-04-07T13:57:18","date_gmt":"2023-04-07T17:57:18","guid":{"rendered":"https:\/\/www.warbyparker.com\/learn\/?p=1580"},"modified":"2026-04-02T03:12:34","modified_gmt":"2026-04-02T07:12:34","slug":"what-are-prism-glasses","status":"publish","type":"post","link":"https:\/\/www.stage.warby.io\/learn\/what-are-prism-glasses","title":{"rendered":"What Are Prism Glasses?"},"content":{"rendered":"\n

Prism glasses are prescription eyeglasses<\/a> with special lenses for correcting double vision (also known as diplopia). In some cases, prism glasses may also be prescribed to help with eye strain (depending on the cause).<\/p>\n\n\n\n

Standard prescription lenses correct for visual clarity\u2014vision errors like nearsightedness<\/a>, farsightedness<\/a>, or astigmatism<\/a> (also called refractive errors). Prism lenses, on the other hand, correct for eye alignment or movement issues, not refractive errors. Sometimes when eyes aren\u2019t aligning correctly, they can\u2019t work together properly to create a single image. And that\u2019s where prism glasses come in.<\/p>\n\n\n\n

We\u2019ve put together this handy guide to walk through everything you might want to know about prism glasses\u2014from how they work and who they help to what prism correction looks like on a prescription (and everything in between). <\/p>\n\n\n\n

How Do Prism Glasses Work?<\/h2>\n\n\n\n\n\n

Prism glasses work by redirecting light before it enters the eye so that it hits the retina at the correct focal point. The prism is shaped like a three-dimensional triangle with a base that\u2019s thicker than the top. The prescription determines the orientation of the prism in the glasses lens (base up, base down, base in, or base out). The prism\u2019s orientation affects how the lens directs light onto the retina.<\/p>\n\n\n\n

A prism correction may be used for one or both eyes. When prism correction is needed as a long-term solution, it can be incorporated into the lens(es) of a person\u2019s glasses. <\/p>\n\n\n\n

Sometimes a prism correction is needed only temporarily. In these cases, a Fresnel prism can serve as an alternative to prism glasses. Fresnel prisms are like thin stickers that can be applied directly to the surface of the lenses of standard glasses.<\/p>\n\n\n\n

Prism Glasses for Double Vision<\/h3>\n\n\n\n

Double vision happens when a person\u2019s eyes aren\u2019t working together the way they should. Instead of seeing a single image, they see two separate images because the light is hitting each eye\u2019s retina in a different spot. Prism eyeglasses correct for this to create a single, clear image.<\/p>\n\n\n\n

Who Needs Prism Glasses<\/h2>\n\n\n\n

Many eye conditions or health issues can cause double vision, and not all of them can be corrected with prism glasses. With that said, some conditions that may benefit from prism correction include:<\/p>\n\n\n\n