Retro Reading Glasses

Did you know; reading glasses lenses correct your vision by bending the light entering your eye? The level or amount of light being bent is referred to as the “Refractive Index”, or just “Index”. Why is this important and more importantly how does this impact wearers of high power reading glasses? Read on and learn more.

Diopters
The strength of blue blocking reading glasses is referenced in “Diopters’, this is a direct correlation to the lenses “Index”. These Diopters are also referred to as the “Reading Power” or “Reading Strength”, don’t worry they are all the same thing, different makers of reading glasses just refer to them differently. You will also see the Diopter referenced with a “+” sign and even in rare cases the word “add”. So if you see a pair of readers marked “+1.50” these are 1.50 Diopter reading glasses.

Reading glasses usually start at +1.00 as this is a typical entry level diopter for people to start wearing readers. While this is a typical entry point it does not mean it is the most ideal. Reading glasses can be found as low as +0.25 but people will usually just squint through reading past the point where this power would be appropriate, but by the time they reach +1.00 the need for vision correction can no longer easily be ignored.

Lenses
So back to those lenses, the Index and higher power reading glasses. In almost all cases the higher the Diopter the thicker the lenses need to be to achieve the correct Index to achieve the appropriate vision correction. Two of the most common, and lower price, lens types are plastic and glass. Plastic lenses have Refractive Index of approximately 1.50 while glass is slightly higher at 1.52. This Refractive Index determines how much of the material is needed to achieve the correct magnification. The lower the number the more material is needed. So a lens made with material with a higher Refractive Index will be more slim at the same Diopter as a lens made with a lower Refractive Index.

Reading Glasses Strength
The most common power of reading glasses in use today is the +1.50 with the average being in the range of +0.75 to 2.00. Because of this many makers of reading glasses do not bother to make readers in powers higher than +2.50 because they cannot sell enough to warrant making them. But this leaves customers whose eyes need these higher powers out of luck.

Women Wearing High Power ReadersHigh Power Reading Glasses
Now that you know a little more about lenses and Diopters and the Refractive Index it will make a lot more sense when we tell you that Visualites readers with their Polycarbonate lenses are noticeably thinner, especially at Diopters +3.00 and up in comparison to reading glasses made with plastic or glass. High Power Reading Glasses generally refer to +3.00 reading glasses, +3.50 reading glasses and +4.00 reading glasses. It is rare to need more magnification than +4.00 and those who do may have a condition such as astigmatism or macular generation. You should always have your eyes regularly checked by a professional but if you find yourself needing higher than +4.00 reading glasses and have not had your eyes checked within the past year it is wise to consider getting that done.

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