Are you among those who wondered if individual free-form progressive lens (PAL) designs are discernibly better than conventional designs or optimized free-form designs that use default values? Have you wondered what effect position of wear measurement errors have on these complex PAL designs?
We have much to offer patients to help them see, feel and look better in their glasses. But we often overlook how eyewear can help patients care for their eyes. Are your patients aware that excess exposure to UVR and HEV blue light can affect their eyes negatively and lead to irreversible damage over time? Are they aware that the damage is cumulative and that protecting the eye from this harmful light should start young? The answer is no; few are aware, but you can change this with a simple statement. It starts with you explaining that we all need to care for our eyes to lower our risk of developing sight-robbing conditions later in life. Then, tell them you recommend photochromic lenses to all your patients, starting with kids, because of the high-level protection they provide for our eyes from harmful sunlight.
Historically, producing optically viable high-wrap eyewear was limited and required specialty labs (especially for progressive lenses). Conventional manufacturing methods were only capable of generating a sphere or torus on the back surface of the lens. Therefore, only a narrow range of prescriptions could be produced in high-wrap frames. Labs that dealt in high-wrap eyewear used formulas to calculate and compensate for the power error and oblique astigmatism caused by the angle formed between the visual axis and the lens optical axis in the primary gaze position. They also added equal and opposite prism to cancel the induced prism. Later came aspheric designs that improved peripheral optics when they fit correctly but still had room for improvement.
Digital free-form lenses have existed since 2000, yet the terms used to define concepts related to these highly technical lenses still confuse us. For example, opticians use the terms personalization and compensation interchangeably, but they are different yet often related concepts.
You can’t judge a book by its cover, but ECPs certainly judge a lab by its AR coatings! As eyecare professionals, we help the patient match their prescription to the best frames and lenses, and even marry visual lifestyles to specific lens designs. We are so fortunate to have many design options that cater to maximizing the visual efficacy for distance, intermediate, near, computer, driving, sports and more. The engineering behind these design options enables us to offer our patients the best of the best, personalized to their visual needs and wants. But how often do we talk about the varying details of the icing on the cake: anti-reflective coatings?
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