High Index Lenses

Eyeglass Lens Thickness, is it really Noticeable?

If you have a strong corrective vision prescription, it’s a good bet that you’re aware of the negative effects of thick lenses and the “standard materials verses high index materials” debate.

How Noticeable is Eyeglass Lens Thickness?

But is lens thickness really that noticeable to others? Several factors affect the answer; the strength of your prescription, and prescription type, and your frame selection.

It’s no mystery that the stronger your prescription is, the thicker your lenses (if made of standard glass or plastic) will be. So if your prescription is relatively mild or only moderately high, lens thickness may not be too much of an issue. Higher prescriptions, however, and by default thicker lenses, will start to become more and more noticeable. “Noticeability,” in this case, is defined by a few factors.

First, the physical thickness of the lens becomes noticeable when it extends beyond the frame that surrounds it. Semi-thick lenses may not stick out all that much, especially if your frame tends to be of the thicker variety. But chunkier lenses will protrude from the frames and be especially noticeable at the frame sides, where the indentations of your orbital bone provide a natural recess or open space. If your lenses are very thick they will extend outward fairly far from the frame, and this peripheral “viewing area” will make them all the more obvious.

Related to the above, lens thickness may affect your choice of frame styles. Extra-thick lenses are too thick and heavy to be supported by rimless or semi-rimless frames. This is not technically a “noticeability factor,” but it does limit your frame style selection and thus becomes a matter of aesthetic appearance.

Also, your frame style will affect the apparent thickness of your lenses by allowing you to adjust the degree to which you “hide” your lenses. If you have a thick plastic frame surrounding the lenses, it can cover all or most of the lens; patterned or darkly-colored frames also accomplish some disguising “sleight of hand,” since they draw the focus away from the lenses. If, however, you prefer a thin metal frame style, your lenses will be completely exposed at the sides.

Thick lenses are also noticeable from the front in terms of their penchant for acting as magnifying lenses. “Coke Bottle” lenses, as they’re not-so-affectionately known, magnify the area behind them and make your eyes appear unusually large. “Tiny Eye” lenses have the opposite effect, reverse-magnifying so that your eyes appear small in relation to the rest of your face and head. If your prescription is strong enough to produce either of these effects, thinner high index lenses may be the way to go.

Lastly, the type of corrective vision you require plays a role in lens thickness. If you’re farsighted, your lenses might not appear to be extremely thick even with a strong prescription. Lenses constructed to compensate for nearsightedness, however, are a different story. They’re thin in the center but grow gradually thicker as they curve out towards the ends, and the edges are the thickest parts of this type of lens. With a strong prescription for nearsightedness, lens edges can be prohibitively and noticeably thick. The question of “how thick is too thick” is really up to you.