Optical distance & ergonomics
The Ergonomic Eye
Enter your prescription to see how far you can see clearly, preview your own vision, and get a desk setup, daily routine and product recommendations tailored to you.
FreeNo loginWorks on any device
💡
Did you know?
Myopia is projected to affect nearly 5 billion people — half the world’s population — by 2050, roughly double the ~2 billion cases in 2010. Holden et al., Ophthalmology, 2016Your prescription
Enter what is printed on your prescription for the right eye (OD, oculus dexter) and left eye (OS, oculus sinister). SPH = sphere power in diopters (D), the lens strength: negative is myopia, positive is hypermetropia. CYL = cylinder power for astigmatism and AXIS = its angle (1–180°). ADD = extra near power for presbyopia. PRISM = prism power in prism diopters (Δ) with its BASE direction. PD = pupillary distance in mm between your pupils. Leave any field blank if it is not on your prescription.
Other diagnosed eye or related conditions (optional)
Select any that apply — these adjust your ergonomics notes, product suggestions and daily exercises below. Leave all unchecked if none apply.
Screen & profile details
Important limitation: this is an educational estimate, not a clinical vision test or diagnosis. The clear-range calculation uses spherical equivalent (SPH + CYL/2) and a fixed 4.00 D accommodation reserve; it does not fully model astigmatism, age-related accommodation, binocular vision, eye disease, or individual focusing behaviour. The simulator illustrations are conceptual, not a validated prediction of what you personally see. Do not use these results to choose, change, or delay prescribed care; consult an eye-care professional for an assessment.
Your clear-vision range
The near point and far point are the closest and farthest distances each eye can focus sharply without glasses. For astigmatism the spherical equivalent (SPH + CYL/2) is used. ADD lowers the estimated accommodation reserve. Anything outside the window looks blurry.
Screen & desk ergonomics
Desk and monitor guidance based on the more limiting eye, plus notes for astigmatism, ADD, prism and PD. Near PD is your PD narrowed for close viewing, and is used when ordering computer or reading lenses.
Display & colour settings for your screen
Workspace Check
Eye comfort is only part of a healthy workspace. This section covers posture, movement, keyboard and mouse position, room lighting and on-the-go setups, all sourced from OSHA, CCOHS and a 2015 international expert consensus on desk-based work (Buckley et al., British Journal of Sports Medicine).
0%
Posture score
0 of 5 checks done
Posture check-in
Tap each card as you check it off at your desk.
Standing desk timer
How this works
- Sit and work as normal.
- After about 30 minutes of sitting, stand up or walk around for a short stretch. Choose how long below.
- Press Start when you stand. The bar fills in proportion to the time you spend standing (one minute is under 1% of a 2-hour bar, so the exact time is shown beside it), and the timer stops by itself when your stretch ends.
- Your total for today is saved in this browser and starts again tomorrow.
A 2015 international expert consensus (Buckley et al., British Journal of Sports Medicine) suggests starting at about 2 hours of standing or light movement across a working day, which is about a quarter of an 8-hour day, and building toward 4 hours over time. It also warns against sitting still for long stretches and against standing still for long stretches, so mix sitting, standing and walking. It does not fix one exact cycle, so the 30-minute rhythm here is a simple, practical choice rather than a rule.
Stand for this long each time
Daily goal
0 s of 2 hours standing today
🪑
Stand & move
Press Start when you stand up. Walk, stretch or just stand until the timer ends.
10:00
Keyboard & mouse setup
Room lighting & glare guide
Tap the option closest to your real setup.
Working away from a desk
Live vision simulator
The text in every scene is drawn at its real size and seen from the distance shown. Blur is calculated from your prescription with standard optics: how much focusing your eye can supply, the defocus left over in each direction (so astigmatism can never be focused away), and your pupil size. The caption under each picture gives the defocus in dioptres (D) and the blur size in arcminutes (60′ = 1°). Other conditions use the stage or type you choose in "Your prescription". They are illustrations, not measurements.
How accurate is this simulator?
- Sharpness: blur comes from standard geometric optics using your sphere, cylinder and axis, the distance of each scene, the focusing reserve your eyes have (4 D, less if you entered an ADD) and pupil size (4 mm indoors, 3 mm outdoors).
- True size: the text in each scene is drawn at its real size, so the blur is in the right proportion to what you are trying to read, whatever size your own screen is. The phone and laptop bodies are illustrations.
- Astigmatism: the eye picks the focus that centres the blur, so astigmatism can never be focused away. Where it still blurs one direction more than the other, the stretch follows your axis as seen from the wearer’s side.
- Limits: real eyes have small extra imperfections and the brain adapts to blur it has lived with, so your own experience can be a little better or worse. Pupil size also changes with light and age.
- Other conditions: typical stages that you choose. The equivalent blur used for cataract and amblyopia is anchored to published data (about 20/43 at 1 D of defocus) and is approximate. Colour vision uses the Machado, Oliveira and Fernandes (2009) model.
Try your own viewing distance
Viewing from 60 cm0 px
15 cm60 cm100 m
📊
Did you know?
A 2023 meta-analysis of over 66,000 people across 103 studies found that about 7 in 10 computer users experience Computer Vision Syndrome (digital eye strain) symptoms. Pmc.ncbi.nlm.nih.gov, meta-analysis, 2023What colleagues see
Curious what a teammate with different glasses sees? Drag the sliders to try any prescription — sphere, cylinder, axis, add and prism — and watch four everyday scenes change. It is one shared set of sliders, separate from your own eyes above, and shows the view without glasses.
Your daily action plan
🔔 Smart reminders
A short, personalised set of eye exercises based on the conditions you entered above. Each card has its own timer — press Start and follow along; a sound and flash mark when a step ends. These support comfort and habits, and are not a treatment.
Recommended for your profile
Suggestions that change with your prescription — high-index lenses for strong powers, computer or progressive lenses for screen work and ADD, and more. Discuss these with your optician before buying.
Eye Exam Planner
How often you need an eye exam depends mainly on age and whether you have any risk factors (wearing correction, or a condition you selected above). Based on American Optometric Association (AOA) guidelines, with American Academy of Ophthalmology (AAO) guidance noted where it differs. This is general guidance, not a diagnosis of when you personally must go.
What to bring or mention at your next exam
Save, print & share your results
Save this result
Saved prescriptions and some preferences/reminder counters are stored in this browser, not sent to a server by this page. Avoid saving on a shared device. You can delete the prescription history below; clearing this site’s browser data removes other locally stored items.
Print or save as PDF
Opens a polished, detailed report. In the print dialog, choose Save as PDF to download a PDF file.
- Your prescription for both eyes
- Clear-vision range and simulated scenes
- Your action plan and recommendations
Share or download a result card
A compact visual snapshot of your estimated range, eye-focus illustration, workspace tip, action plan and a “Try it yourself” prompt.
- Prescription for each eye
- Near and far clear-vision points
- Share straight to WhatsApp, Gmail and more, or save as a PNG
Embed this calculator
Paste this on your own page or blog. Note: some sites block embedded content for security reasons, so this may not display everywhere; sharing the direct link is the more reliable option.
How your eyes focus light
A simplified cross-section of each eye, not an anatomically exact picture. It shows where light comes to a focus relative to the retina, and how your correction fixes it. Switch between uncorrected and corrected, and between looking far away and at something 40 cm away. ADD (reading power) only shows up close. Prism shifts the image across the retina, and the correction moves it back to the centre.
Schematic, not to scale. The focus distances in dioptres (D) are calculated from your prescription. ADD only matters up close, and prism shifts where the image lands on the retina.
Right eye (OD)
Left eye (OS)
Trends & patterns
Two charts built from your own numbers. The first compares the focusing reserve estimated from your prescription (the tool’s standard 4 D, lowered by any ADD you enter) with the typical range for your age. The second shows where your prescription (both eyes) sits on the standard mild, moderate and high scale. Neither chart predicts how your own eyes will change over time.
Your focusing power vs. the average by age
Where your prescription sits in the general population