Digital Lenses & Prescription Sunglasses

What makes a digital lens different?

Digital, or free-form, surfacing lets a laboratory calculate and manufacture complex lens surfaces with precise control. Depending on the design and measurements supplied, a lens can account for prescription, frame shape, and how the frame sits in front of your eyes. Two lenses can look very similar while distributing clear viewing areas and peripheral blur differently.

A randomized, double-masked crossover study of 95 experienced progressive wearers found a preference for the customized free-form lenses tested and a wider clear reading field. Standard clinical vision tests showed no clinically important differences. The study tested a particular ZEISS design against a particular conventional lens; it supports the value of personalization without establishing that every digital lens, or every Shamir product, outperforms every alternative. Read the original 2011 clinical trial.

The Shamir lenses we use

These product descriptions come from Shamir’s technical information. A manufacturer’s design claim and an independent clinical outcome answer different questions. We discuss the available options and check how the finished pair works for you.

Clear viewing areas and progressive corridors

A progressive lens changes power from distance to near through an intermediate corridor. Its design balances the widths of useful viewing areas, the rate of power change, and peripheral astigmatism. A well-chosen design can give you more usable vision for the task you prioritize; corridor length alone is not a quality score. Frame depth, reading posture, prescription, and adaptation all influence the experience.

In a double-blind study of 51 people, changing personalized progressive designs changed measured or perceived viewing-zone widths, blur gradients, and distortion. Participants generally preferred the personalized lenses tested. These results apply to the specific Rodenstock designs tested. Read the original design study.

Why a millimeter can matter

Your monocular pupillary distances locate each eye horizontally. Fitting heights locate the lens design vertically in the adjusted frame. Lens-to-eye distance, tilt, wrap, and a frame that stays in position also influence the result. A one-millimeter shift can matter, especially with a strong prescription, unequal powers, or a progressive lens. Its effect varies with the prescription and direction of the error; it is not a universal threshold for discomfort.

For a simple single-vision example, Prentice’s rule gives induced prism as decentration in centimeters multiplied by lens power in diopters. Looking one millimeter away from the optical center of a 6.00-diopter spherical lens produces 0.6 prism diopters of displacement. This illustrates the optics; it does not predict how every wearer will feel. A progressive-height error additionally changes which part of the power progression you look through.

With a high cylinder prescription, accurate cylinder axis and stable frame alignment deserve particular attention. A controlled study found that tolerance of axis misalignment depended on cylinder power. Axis rotation is measured in degrees and is a separate issue from a millimeter error in PD or fitting height. Read the astigmatism and axis study.

Trivex, 1.67, and 1.74: choosing the material

We recommend Trivex for many patients because it combines low weight, impact resistance, UV protection, and good optical clarity. Its relatively high Abbe value means less color dispersion than some alternative materials, which can help limit colored fringes when looking away from the optical center. It is also useful for many drilled and rimless frame designs. PPG’s material information.

For stronger prescriptions, we often consider 1.67 or 1.74 high-index lenses to reduce thickness. The result also depends on frame size, shape, centration, and the prescription. Higher index is one property to balance with weight, optical dispersion, durability, and the available designs and coatings. A smaller, well-centered frame can make a substantial difference.

PPG and HOYA’s laboratory work compares Trivex and polycarbonate under specified impact and material tests. It is manufacturer-supported laboratory evidence, with results applying to the tested products and conditions. Every lens needs appropriate care; sports and workplace hazards require a complete, appropriately rated protective-eyewear system. Read the manufacturer’s testing summary and white-paper link.

Glacier Expression anti-reflective coating

Glacier Expression is our primary anti-reflective coating. Anti-reflective treatment reduces reflections at lens surfaces, helping more light pass through and making your eyes easier to see through your glasses. Shamir also describes surface treatments intended to make cleaning easier. Coating performance depends on its construction, application, and care. Shamir Glacier Expression information.

Ask us about care and the warranty for your particular order. Heat, abrasive cleaning, and chemicals can damage lenses or coatings, including premium ones. Use the recommended cleaner and a clean lens cloth, and keep glasses out of a hot parked car.

Blue Zero: what the filter does

We use Shamir Blue Zero for many orders. It incorporates a blue-violet-light filter in the lens material, alongside UV protection. Material, design, and prescription availability determine the combinations we can order. Read the manufacturer’s specifications.

Filtering a wavelength and improving a health outcome are separate claims. A double-masked randomized trial involving 120 symptomatic computer users found no eye-strain benefit from blue-blocking spectacles compared with clear lenses during a two-hour computer task. We recommend appropriate correction, comfortable working distances, breaks, and assessment of dry-eye symptoms for screen discomfort. Evidence does not establish blue-filtering spectacles as prevention for macular degeneration. Read the original eye-strain trial · Dry-eye care at Midtown.

Yes, we make prescription sunglasses

You can have your distance prescription or an appropriate progressive design made as sunglasses. We help select a compatible frame, tint, material, UV protection, and polarization. VSP benefits may be used toward prescription sunglasses, depending on your plan, eligibility, allowances, and lens enhancements. Our team checks your benefits and explains your share before ordering. VSP and eyewear at Midtown.

Polarized lenses reduce reflected glare from surfaces such as water and roads. They can be useful for daytime coastal outings and driving. Polarization and UV protection are different properties; choose sunglasses with appropriate UVA/UVB protection. Polarized lenses can affect the visibility of some screens and displays, so try the combination you use. Sunglasses are for suitable daytime light conditions.

A small study of 45 young adults found no significant improvement in measured visual acuity, stereopsis, or phoria with polarized versus other test conditions. Practical glare control should therefore be distinguished from promises of sharper chart vision or disease prevention. Read the 2025 polarized-sunglasses study.

Choose the complete pair

We consider the prescription, lens design, material, coating, frame fit, and follow-up together. Read our balanced comparison of Midtown, Costco, and Warby Parker eyewear options, or explore photographs from our collection.