notes.
Plain-English science on contrast sensitivity, vision, and the screening tool we built. Cited where it matters, honest about what isn’t settled.
Wide-gamut displays (P3 and Rec.2020) and at-home vision tests
Your new laptop has a wide-gamut P3 screen. Does that help or hurt an at-home contrast test? The answer is about tone reproduction, not color range.
When to push for a vision referral: neuro-optometry, neuro-ophthalmology, or low-vision
Three specialties, three different jobs. A patient's guide to when to ask for neuro-optometry, neuro-ophthalmology, or low-vision rehabilitation.
What orthoptics is, and where orthoptists fit in your eye care
You were referred to an orthoptist and are not sure what that is. Here is what orthoptics covers, who orthoptists work with, and where they fit in eye care.
Weber vs De Vries-Rose luminance regimes, in plain English
Why the same eyes score differently at different screen brightness: in dim light contrast threshold follows a square-root law, in bright light Weber's law.
Thyroid eye disease: early visual signs worth knowing
Thyroid eye disease can quietly affect the optic nerve. Here are the early visual signs — color, contrast, dimming — and why they precede vision loss.
Sports vision and contrast sensitivity: beyond 20/20 acuity
Athletes need more than 20/20. Contrast sensitivity shapes how you pick a ball out of a busy, dim, or bright background, and it's a signal you can track.
Returning to screens and work after a concussion: a graded re-introduction
After a concussion, screens can trigger symptoms. Here is a graded, symptom-limited way back to reading, devices, and work — and where a vision check fits.
Retinitis pigmentosa: why night vision and contrast fade first
Retinitis pigmentosa damages rod cells first, so night vision and dark adaptation fade early. Here is how contrast sensitivity fits as a functional signal.
How to read a longitudinal contrast sensitivity graph: a worked example
Four dots on a chart tempt you to see a trend that isn't there. A worked example of reading your own contrast sensitivity over time — signal, noise, and shape.
Ten questions to ask your eye doctor
The right questions turn a routine eye exam into a real conversation. Ten specific things to ask your optometrist or ophthalmologist — and why each one matters.
Posterior capsule opacification and the YAG laser: why vision can cloud again
Months or years after cataract surgery, vision can slowly cloud again. It is usually posterior capsule opacification, and a quick YAG laser clears it.
Perimenopause and vision: the contrast layer
Vision changes are an under-discussed part of the menopause transition. What the evidence supports on hormones, dry eye, and contrast — and what it doesn't.
OLED near-black behavior and why it matters for home vision testing
OLED screens have perfect blacks and stunning contrast. But their near-black behavior and auto-brightness limiting can quietly bias an at-home contrast test.
OCT vs fundus photography: which catches what
OCT and fundus photography are the two images your eye doctor takes of your retina. Here's what each one catches — and what neither of them can measure.
Night vision and contrast after LASIK or PRK
Some people notice halos, starbursts, and dimmer low-light vision after LASIK or PRK. Here is why it happens, why it usually fades, and how to track it.
logMAR vs Snellen: two ways to score visual acuity
logMAR and Snellen both score the smallest letters you can read, but on different scales. Here's why researchers switched — and what it means for your number.
Keratoconus and Higher-Order Aberrations: Why the Eye Chart Misses It
Keratoconus induces higher-order aberrations like coma that smear the retinal image and lower contrast sensitivity while Snellen acuity can still look fine.
How to read your eye exam report: a patient's guide
OD, OS, SPH, CYL, axis, add, IOP, C/D ratio — your eye exam report is dense with abbreviations. Here's a plain-English glossary of what each one means.
Home vision tests compared: acuity, color, Amsler grid, and contrast
Acuity apps, color plates, the Amsler grid, and contrast tests each measure something different. What each one catches, what it misses, and how to use them.
Blood sugar (HbA1c) and contrast sensitivity
Contrast sensitivity can drop in diabetes before retinopathy shows up on an exam. Here's how blood-sugar control (HbA1c) connects to this early functional signal.
Halos and starbursts after cataract surgery: what dysphotopsia is
Seeing halos, starbursts, or a temporal shadow after cataract surgery? These are called dysphotopsia. Here is what causes them, and what usually happens next.
Fuchs' dystrophy and morning glare: why vision clears through the day
Fuchs' dystrophy can make vision haziest on waking and clearer by afternoon. Here is why overnight corneal swelling scatters light and lowers contrast.
FL-41 and tinted lenses for photophobia: what the evidence actually says
FL-41 rose tint is the most-studied lens for light sensitivity. Here is what the evidence supports, where it is thin, and how to try tints without making things worse.
Eye strain causes: a differential for tired eyes
'Eye strain' is a symptom, not a diagnosis. It could be digital eye strain, presbyopia, dry eye, or a real contrast change. Here's how to tell them apart.
Epiretinal Membrane: When the Retina's Cellophane Blurs Contrast
An epiretinal membrane can leave acuity near normal while it warps the macula, bending lines and dulling contrast. Here is what that functional signal means.
Drusen on a routine eye exam: what it means and what to do next
Your eye doctor mentioned drusen. Here is what those yellow deposits mean, how size changes the risk, and the practical next steps — without the panic.
Contrast sensitivity vs visual acuity vs visual field: what each measures
Three core vision measures, three different questions. How acuity, contrast sensitivity, and the visual field each map a different part of how you see.
Color vision vs contrast sensitivity: what each one tells you
Color vision and contrast sensitivity probe different visual machinery. See what each home test catches, what it misses, and how the two can dissociate.
Choosing an IOL: monofocal vs multifocal vs EDOF, a pre-op primer
Before cataract surgery you have to choose a lens implant. Here is the plain-English trade-off between monofocal, multifocal, and EDOF lenses — and the contrast angle.
Anti-reflective coatings and night-driving vision
Do anti-reflective coatings actually help you drive at night? What they fix, what they don't, and why the yellow 'night-driving glasses' story is different.
Adapting to new progressive lenses: the two-week window
New progressives can feel dizzying at first — swimming edges, a narrow sweet spot. Here is why, how the two-week adaptation works, and when it is a fitting problem.
Acute uveitis: when light sensitivity is a red flag
Most light sensitivity is benign. But a painful, red, light-sensitive eye can signal acute uveitis, which needs prompt care. Here is how to tell the difference.
Why your screen settings matter: calibration in remote vision testing
Why a remote contrast sensitivity test has to calibrate to your screen — and what each calibration step is actually preventing.
Why we don't store your test results (and why some products do)
Most online tests silently keep your results on a server. We don't — and we want to be explicit about what that means, the trade-offs, and what would change.
Why we built a free, open contrast sensitivity test
There is a real visual measurement most eye exams skip, the popular online version of it is broken, and the fix turned out not to be hard. So we wrote one.
Why visual acuity (20/20) is a misleading single number
20/20 is a real measurement of one specific thing. It is also a single point on a multidimensional function — and most of what vision does happens elsewhere.
Why one test isn't enough: tracking contrast sensitivity over months
How to read your own contrast-sensitivity record across months — variance sources, pattern types, regression to the mean, and when a trend is worth acting on.
What contrast sensitivity actually measures (and why visual acuity isn't enough)
Visual acuity samples one point on a curve. Contrast sensitivity measures the whole curve — the difference between passing an eye chart and seeing well.
Visual snow syndrome: when 'static' is constant, and what it means for contrast
Visual snow syndrome is real, continuous, and underrecognized. What the literature says, what's mapped, and where contrast sensitivity fits in honestly.
Vision and brain fog: when 'feeling foggy' has an eye component
Brain fog often has a quiet visual component. Here's how contrast sensitivity can surface a vision layer you might not have noticed — and what to do with it.
Contrast sensitivity in children: what we know
Children's contrast sensitivity matures over years. Here is what the research shows, where amblyopia fits, and why our test is built for adolescents and adults.
Tick-borne co-infections and vision: what the literature shows
Bartonella, Babesia, Anaplasma, Ehrlichia, and Rocky Mountain spotted fever can affect the eye. Here is what the peer-reviewed literature actually documents.
Task lighting for contrast: practical setup for reading, working, and aging eyes
A practical guide to lighting your home for contrast — lux, color temperature, CRI, flicker, lamp placement. What to buy, what to skip, and why it matters.
Spatial frequency in plain English (and why 3 cpd matters)
Cycles per degree, in three panels. What spatial frequency really means, why human vision peaks around 3 cpd, and where the cliffs at each end come from.
Self-tracking vision: a beginner's guide for chronic-illness patients
A practical, sourced guide for chronic-illness patients on tracking your vision over time — what to measure, how often, how to bring the trend to a clinician.
Why screens at night feel different (and what your eye is doing)
Same screen at midnight feels brighter, harsher, harder to read than at 3 p.m. What your visual system is doing — and what evidence supports for dark mode.
The science of grayscale: how monitors lie about contrast
Why #808080 is not 50% gray, how sRGB and gamma curves quietly bend reality, and why OLED, LCD, and HDR each lie about contrast in a different accent.
Reading the Campbell-Robson chart: how to see your own contrast sensitivity function
An interactive eye exam you can do with one image. The Campbell-Robson chart makes your contrast sensitivity function visible — here is how to read it.
Reading glasses won't fix this: distinguishing focus problems from contrast loss
Your new readers make the page sharper but reading still feels harder than it should. Here's how to tell focus problems from contrast loss — and what to ask.
Progressive lenses and contrast: the trade-offs nobody mentioned
Your progressives sharpened reading but something else feels off — depth, peripheral motion, dim-light contrast. Here's the lens-design trade-off behind it.
Vision changes after a concussion: when contrast sensitivity tells you something
After a concussion the eye chart often looks fine while the world feels different. Contrast sensitivity is the measurement that can register what acuity doesn't.
Cataract surgery IOL choices: what to expect for contrast
Monofocal, multifocal, EDOF, toric, light-adjustable: a patient-respectful tour of how each cataract-surgery IOL changes the contrast you will see for life.
Photophobia: why light hurts, and what it has to do with contrast
Light shouldn't hurt — but for migraine, post-concussion, and dry-eye patients it often does. The neuroscience, the conditions, and where contrast fits in.
Pelli-Robson vs FACT vs qCSF: a tour of the major contrast sensitivity tests
Pelli-Robson, FACT, and qCSF are the three main contrast sensitivity tests. They measure different things at different precision — and their numbers do not interchange.
A patient's guide to bringing your CSF result to your eye doctor
You took the test and you have a number. Here is a practical guide to bringing it to your next eye-care appointment so the conversation that follows is better.
What a neuro-optometric rehab appointment actually looks like
Someone told you to see a neuro-optometrist. Here is what the appointment involves, what therapy looks like, what it costs, and what the evidence says.
Mold, CIRS, and the Shoemaker contrast pattern: what is and isn't established
A careful, sourced look at the contrast sensitivity claim in CIRS — what the framework proposes, what the literature supports, and what is still contested.
Migraine aura and contrast sensitivity
Between attacks, many people with migraine show subtle contrast-sensitivity differences. A careful tour of what the interictal literature does and doesn't show.
Lyme disease and vision changes: what the literature shows
Acute Lyme has documented ocular findings. Post-treatment Lyme is contested terrain. Here is what the peer-reviewed literature actually says about vision.
Low light, low contrast: why poor lighting hits some eyes harder
Dim rooms, twilight, parking garages. The same eye performs differently as light drops — and the gap between people widens. Here is the physiology behind it.
Long COVID and contrast sensitivity: early reports and open questions
Emerging Long COVID research has begun looking at contrast sensitivity. The literature is small and early. Here is what is reported and what remains open.
How to take a contrast sensitivity test online (and what the result means)
A step-by-step guide to taking a contrast sensitivity test in your browser — what good calibration feels like, and how to read your CSF curve once it's drawn.
Hello — what this blog is for
A short note on what this blog covers — contrast sensitivity in plain English, what the science says, and what it doesn't.
Glaucoma and contrast sensitivity: an underused early signal
Glaucoma can damage the optic nerve before standard tests catch it. Contrast sensitivity sometimes registers that early signal — but it's no substitute for an eye exam.
Glare disability: when bright light is the visual problem, not the solution
Bright light is supposed to help you see. For some eyes it does the opposite. Here is the physics of glare disability, and the testing the eye chart skips.
Five conditions that quietly affect contrast sensitivity
Five common conditions quietly degrade contrast sensitivity — sometimes years before the eye chart notices. What to watch for, and what the science says.
Driving at dusk: contrast sensitivity changes nobody warned you about
The 30-minute window after sunset is when crash risk climbs sharply. Here is what is happening to your eyes in that window — and what to do about it.
Diabetic retinopathy and contrast: what early signs look like
Contrast sensitivity can drop before diabetic retinopathy is visible on a dilated exam. Useful as a self-tracking signal — not a replacement for the exam.
Dark adaptation: the 20-minute curve nobody talks about (and what slows it down)
Walk from sun into a dim hallway and for half a minute you're blind. Twenty minutes later you can see stars. The curve between those two points is gorgeous.
Critical periods in amblyopia: what 'treatment windows' actually mean
The old framing said amblyopia must be treated before age 7. Modern evidence shows a gradient, not a cliff — and meaningful reason for hope past that window.
Contrast sensitivity in MS: what the research says
Contrast sensitivity is a sensitive probe of optic-pathway involvement in MS — often abnormal when acuity is 20/20. A careful tour of the literature.
Concussion recovery: what to expect week by week for vision
A rough week-by-week roadmap of post-concussion vision changes — what tends to be normal early on, when to be patient, and when to escalate to a specialist.
Cataract and contrast: why your eye exam might say 20/20 while you struggle to drive at night
Night driving is harder, but your eye doctor said 20/20. Here's the part of vision the chart doesn't measure — and what to ask at your next appointment.
Caffeine, alcohol, sleep: short-term effects on contrast vision
Three everyday inputs — caffeine, alcohol, and sleep — can nudge your contrast sensitivity reading between sessions. Here's what the science actually shows.
Blue-light filters and contrast sensitivity: what the data actually says
What the 2023 Cochrane review and the contrast-sensitivity RCTs actually show about blue-light glasses for eye strain, sleep, and CSF — and where FL-41 fits.
Age-related macular degeneration: contrast as an early signal
AMD is the leading cause of central vision loss in adults over 50. Contrast sensitivity often slips before acuity does — here's how to use that signal.
Adaptive staircase methods: why one number isn't enough
Why a single fixed contrast level cannot measure threshold, how the 2-down-1-up transformed staircase converges to 70.7% correct, and what we actually run.
AdaptDx in the chair: what a dark-adaptation test actually feels like
Your ophthalmologist mentioned a dark-adaptation test. Here is what AdaptDx measures, what the appointment feels like, what it costs, and what it cannot tell you.
new science, in plain English.
A short, cited note when we publish — contrast sensitivity, vision, and what the research does and doesn't show. No churn.
Unsubscribe anytime. We don't sell or share your address.