01 · PROBLEM FIRST
Find the real problem before choosing a function
Instead of starting with “I want a functional lens,” ask whether the problem is monitor distance, sunlight, surface reflection, frequent indoor/outdoor transitions or night driving.
The situation defines which optical function is relevant.
The starting point is the situation in which the wearer is actually uncomfortable, not a lens catalogue. 'My eyes feel tired' does not distinguish distance blur from a monitor-distance problem, sunlight, reflected glare or prolonged near work. Define when, at what distance and under what lighting the problem occurs before matching a feature to it.
02 · PRESCRIPTION FIRST
A basic prescription problem should be corrected first
If myopia, hyperopia or astigmatism is not corrected accurately, adding a coating or filter does not remove the underlying blur.
It is difficult to judge the value of a functional option if the basic refractive correction is wrong. Uncorrected hyperopia, astigmatism or a changed prescription cannot be fixed by adding a blue-light filter or premium coating. Verify the current correction first, then address the remaining task-specific problem.
03 · MATCH FUNCTION
Match a function to the actual task
Computer and document work → office or near/intermediate-oriented design.
Frequent indoor/outdoor transitions → photochromic lens.
Strong reflections from water or road surfaces → polarized lens.
High-wrap sports frame → lens design that accounts for the wearing angle.
Different lens functions solve different physical problems. Office designs redistribute working distances, anti-fatigue designs add lower-zone accommodative support, photochromics change transmission with light exposure, polarization reduces selected reflected components, and anti-reflective coatings reduce lens-surface reflections. Avoid collapsing all of them into the vague promise of 'less eye fatigue.'
04 · EVIDENCE
Separate optical function from marketing language
Some functions have a clear optical mechanism, while other product descriptions are mainly marketing categories.
Ask what wavelength range is changed, how much light is transmitted, or which viewing distance is being redesigned.
Every function also has a use range and trade-offs. Office lenses can limit far vision, dark tints reduce available light, polarized lenses can interact with displays and photochromics vary with temperature and the vehicle environment. Evaluate what changes or becomes restricted as well as what benefit is gained.
05 · TRADE-OFF
Every function can have an opposite-side condition
Photochromic lenses may not darken strongly inside a vehicle.
Polarized lenses can make some displays difficult to read.
Tinted filters reduce some of the incoming visible light.
The limitation matters as much as the benefit.
The same person may need different priorities in different situations. A day spent at a monitor is not optically equivalent to outdoor activity or long-distance driving, and trying to force every function into one pair may be less useful than separating tasks. Working distance, lighting, indoor/outdoor transitions, driving and sport should guide the decision.
06 · WHOLE SYSTEM
Finish by looking at the entire pair of glasses
Even an excellent functional lens is difficult to use correctly if the frame slips or the PD and fitting position are wrong.
A practical order is problem situation → basic prescription → viewing distance and environment → frame and position of wear → lens design → needed function.
The final result depends on more than the lens feature. First define the distance and environment in which the problem occurs and confirm the basic prescription. Then fit the frame and actual position of wear for those conditions before choosing the lens design and any added function. Keeping that order prevents one choice from undermining another.
SOLUTION GUIDE
GLANOS functional-lens selection order
Describe the actual symptom or situation.
Confirm myopia, hyperopia, astigmatism and any needed addition.
Compare distance, intermediate and near time.
Indoor, outdoor, driving and sports conditions matter.
The goal is not to maximize the number of features.
GLANOS LENS CHECK
A good functional lens is not the lens with the most functions
It is the lens whose functions match the wearer’s actual needs.
CAUTION
Do not select a lens from the product name alone
Identify what the lens physically changes and whether that change matches the intended use.
GLANOS EYEWEAR
There is a reason glasses feel uncomfortable.
functional lenses · office lenses · photochromic lenses · polarized lenses · driving lenses · spectacle lenses