1.74 High Index Single Vision Lenses
If you’re in the market for single-vision eyeglass lenses and have a moderate to moderately-high corrective prescription, 1.74 high index lenses might be just the thing for you.
High Index 1.74 Single Vision Lenses
High index material is used to construct lenses that are thinner and lighter than is possible with standard glass or plastic material, but the higher you go in the index, the higher the cost. 1.74 is the “sweet spot” that takes advantage of the properties of high index without venturing too high up the price scale. For that reason, 1.74 lenses are extremely popular high index choices.
So why might high index lenses be right for you? Well, moderate to high prescription strengths – those that correct for a high amount of nearsightedness or farsightedness – can be relatively thick and heavy. High index lenses bend light more efficiently and can be formed into your prescription with less curvature than standard plastic or glass lenses. This allows for flatter lenses, and because less physical material is needed to shape the curve, lenses that are lighter, as well.
As an example of the thickness comparison, a 1.70 high index lens is about 50% thinner than conventional plastic. 1.74, of course, is even thinner. And a thinner lens means more stylistic options for you. No longer are “Coke Bottle” or “Bug Eye” glasses the only choice for wearers of strong prescriptions; high index lenses can substantially reduce the size, weight, and distortion of standard plastic or glass lenses of the same prescription.
That means that with a 1.74 high index prescription lens you may be able to choose a frame style that otherwise would not be available to you. A rimless or semi-rimless frame, for example, may be possible with 1.74 high index lenses, where standard plastic would produce lenses too thick to be supported by anything other than a thick frame. And the thickest part of your lenses – the edges – would be thinner, as well…so regardless of your frame style choice, your lens edges might not be as obvious and might not protrude nearly as much outside of the frame as a regular plastic lens would.
1.74 lenses do share some of the drawbacks of all high index lenses, of course. The higher price is one, as is a higher Abbe Value (a scale used to rate the degree of chromatic aberration present in optical materials). It’s always a wise idea to investigate all options before deciding on a purchase. If, however, your prescription leaves you in that “sweet spot” to take advantage of the benefits of high index lenses, you may find 1.74 single vision to be the ideal material in your case.