Lens thickness is a problem for me
Do any of these situations sound familiar?
I enjoy choosing nice frames, but my glasses don’t look good because my lenses are too thick.
My lenses add weight to my glasses, so when I remove them they leave red marks on my nose.
I’d like to choose larger frames but I was told that if I do so, my lenses will be thicker.
As lens power increases, so does the lens thickness. But there are ways to make lenses thinner.
It’s true that lenses get their power from their thickness variation. But they also get it from their refractive index and from their optical design. Here are three ways to make lenses thinner:
- Increase the refractive index of the material.
High index lenses require less thickness to get the same corrective power. Standard index lens materials use index 1.5 or 1.56, and high index lenses are 1.6 and above.
- Use an aspheric optical design.
There are three main types of designs for single-vision lenses: spherical, aspherical and dual aspherical. Aspheric optical designs can make lenses thinner by using different curvatures at the center and on the sides. Properly computed optical designs can do this while increasing the optical quality and the sharpness of the lenses.
- Choose a smaller frame.
Due to the shape of the lens, a smaller frame will generally result in thinner lenses. Or, if you’d like to use a larger frame without increasing lens thickness, it’s possible to achieve this with a higher index material and aspheric design.
The Nikon lenses that fit your needs
Nikon offers a wide range of lenses of all indicies, from standard 1.5 to the ultra-high index 1.74 material, which Nikon was the first to launch worldwide.
As higher index lenses are also more likely to reflect light, all Nikon high-index lenses receive a Nikon anti-glare coating that makes the lens very transparent.
Of all the Nikon lenses, the Nikon DAS dual aspheric lenses are the thinnest. They use a dual aspheric design that is up to 14% thinner than ordinary lenses made from the same material.