Zenni’s Blokz lenses start at $16.95, making them one of the cheapest blue light filtering options on the market. Whether that’s money well spent depends on what you’re hoping they’ll do. If you expect them to eliminate eye strain from long screen sessions, the science isn’t on your side. If you want a subtle filter for evening screen use or simply like the peace of mind, the low price makes the gamble painless.
What the Lenses Actually Do
Blokz lenses use a polymer that absorbs a portion of blue light in the 380 to 500 nanometer range. Unlike a simple coating that sits on top of the lens, the filtering material is baked into the lens itself. This means it won’t scratch or wear off over time the way a surface coating might.
Zenni offers several tiers. Standard Blokz ($16.95) absorbs blue light through the lens material alone. Blokz More ($31.90) adds a reflective coating on top of that absorption layer for dual filtering. Blokz Plus Anti-Fatigue ($56.95) bundles blue light filtering with a slight magnification zone at the bottom of the lens, designed to reduce focusing effort during close-up work. You can also add a Blokz Boost coating to compatible lenses for $14.95, and there’s a photochromic version ($29.95) that darkens in sunlight while still filtering blue light indoors.
The Yellow Tint Question
Standard Blokz lenses have a very faint tint that most users describe as barely noticeable and not yellow. The higher-tier Blokz Plus lenses are a different story. Users frequently report a noticeable yellow cast that’s visible from the moment you open the case. If color accuracy matters for your work (design, photography, video editing), the stronger filtering options will shift your color perception enough to be a problem. Stick with the base-level Blokz if you want minimal color distortion.
What the Science Says About Blue Light Glasses
The American Academy of Ophthalmology does not recommend blue light glasses. Their position is straightforward: there is no scientific evidence that light from screens damages your eyes, so no special eyewear is needed for computer use.
A Cochrane systematic review, widely considered the gold standard for medical evidence, looked at 17 randomized controlled trials and reached a similar conclusion. Blue light filtering lenses showed no clinically meaningful difference in visual fatigue scores compared to regular lenses, even over follow-up periods ranging from a single day to five weeks. The review also noted that some participants wearing blue light lenses reported headaches (8% in one study) and discomfort (22% across two studies), though similar complaints appeared in the control groups as well.
The one area where blue light has a real, well-documented biological effect is sleep. Blue light around 470 nanometers suppresses melatonin production, the hormone that signals your body it’s time to sleep. This is why staring at a bright screen before bed can make it harder to fall asleep. But there’s a catch: the amount of blue light your phone or laptop emits is far less intense than sunlight, and most operating systems now offer built-in night mode settings that shift the screen to warmer tones for free.
Where Blokz Might Make Sense
If you already need prescription glasses from Zenni, adding Blokz costs less than a cup of coffee at most cafes. At $16.95 for the base tier, you’re not making a major financial commitment. Some people report that a slight warmth to their lenses feels more comfortable during long screen sessions, even if controlled studies haven’t confirmed a measurable benefit. Comfort is subjective, and placebo effects are real effects when it comes to how your eyes feel at 10 p.m.
The photochromic version at $29.95 offers genuine convenience if you want one pair of glasses that works indoors and darkens outside. It blocks 100% of UV rays and filters blue light, combining two functions into a single lens. That’s a practical upgrade regardless of where you stand on blue light science.
Where Blokz Isn’t Worth It
If you’re buying Blokz specifically to fix dry, tired, or strained eyes after a long day at the computer, you’re treating the wrong problem. Digital eye strain comes from staring at a fixed distance for hours without blinking enough. The solution is the 20-20-20 rule: every 20 minutes, look at something 20 feet away for 20 seconds. Adjusting your screen brightness, increasing text size, and using artificial tears will do more for your comfort than any lens filter.
Paying up for the $56.95 Anti-Fatigue tier is harder to justify. You’re spending nearly four times the base price, and the added magnification zone is a feature that benefits a narrow group of people, mainly those over 40 who are beginning to struggle with close-up focus. If that’s you, it could help. If you’re in your 20s or 30s, you’re paying a premium for something your eyes don’t need yet.
How It Compares to Competitors
Zenni’s main online competitor, EyeBuyDirect, also offers blue light filtering, but adding the filter increases your total cost more than Zenni’s approach. Zenni’s base frames start at $6.95 with prescription lenses included, so a complete pair with Blokz can come in under $25. That’s difficult for any competitor to match. User comparisons generally rate Zenni’s lens clarity and durability slightly higher, though both brands use similar filtering technology.
If you want the sharpest optics possible with blue light filtering, Zenni lets you pair Blokz with Trivex lenses, a material originally developed for military visors. Trivex is lighter, more impact-resistant, and optically clearer than standard polycarbonate. It costs more, but for a primary pair of everyday glasses, the upgrade in visual quality is noticeable.
The Bottom Line on Value
Blokz lenses are not a medical device and won’t protect your eyes from damage that isn’t happening in the first place. Screens don’t harm your retinas. But at $16.95 as an add-on to glasses you’re already buying, the financial risk is minimal. If the slight warmth of the lens makes your evening screen time feel more comfortable, or if filtering some blue light before bed gives you a marginal sleep benefit that your phone’s night mode doesn’t cover, it’s a low-cost experiment. Just don’t expect it to cure eye strain, and don’t pay $57 for the premium tier unless you have a specific reason to need the anti-fatigue feature.