What vision loss looks like
At a glance
Views: Eleven, from full sight to no light perception. Tunnel, center lost, scalloped patches, color gone, distortion, night, and loss from birth.
Stages: Early, mid and late, where a condition progresses. Lighting for the two conditions where light matters more than time; a range for the one present from birth.
Same scene, side by side: Full sight on the left, the condition on the right. So the difference is the only thing that changes. On a phone, drag the slider.
Approximations: Not a diagnosis, not a prediction. A computer-rendered park, changed only by masks and filters. No real person's view is shown.
The simulator
Choose a condition. For the ones that progress, move along the track from early to late. The left view is always full sight; the right one is the same scene as that condition sees it.
A park path curving past a wooden bench and a lamp post toward trees and a distant pavilion, sharp and in full color from edge to edge.
The same park at night: the lamp is lit, and the path, bench and nearest trees are still visible in low light.
Full sight
The reference view
Sharp from the center to the edges, with color, by day and by night. Everything that follows is this scene with something taken away.
Night blindness
Dim places stay dark
Rods see in dim light; without them, anything below the level the cones can detect simply drops out. The lamp and the path it lights are still there. The trees and the sky, which a fully sighted person still makes out at night, are not.
Early: the scene is dimmer than it should be, and sight takes longer to come back after a bright light.
Moderate: only the lit path and the nearest trees remain; the rest is a dark blur.
Severe: only the lamp and the pool of light beneath it. Everything outside direct light is gone.
Nyctalopia. Usually the first sign of retinitis pigmentosa, choroideremia and Usher syndrome, years before the field narrows.
Retinitis pigmentosa
Night first, then the edges close in
Rods go first, so night vision fades years before anything else; then the outer field narrows from the middle distance inward. The center can stay sharp a long time, which is why someone may read a sign across the park yet not see the bench beside them.
Early: by day the field is nearly full, and a ring of weakened sight in the middle distance is easy to miss. In dim light the loss is already obvious; see Night blindness.
Mid: a field of roughly 20 to 25 degrees, close to the legal definition of blindness by field, with the center still sharp.
Late: a central island under 10 degrees, often with a small island of sight at the far edge, and the center itself begins to soften.
Rod-cone dystrophy. The dark is not something they see; it is where nothing is seen.
Watch Retinitis pigmentosa progress. (laneId) => `Full sight to ${VIDEO_END_STAGES[laneId]} stage in about 10 seconds. The real course takes years, and many people never reach the last frame.`
Usher syndrome
Hearing, then the RP pattern
Usher syndrome pairs hearing loss from birth or childhood with the retinitis pigmentosa pattern in the eye: night vision first, then the edges close in while the center holds.
Early: a nearly full field by day, with the loss already obvious in dim light.
Mid: a field of roughly 20 degrees, dim outside the center.
Late: a small central island, with a last island of sight at the edge.
Types 1, 2 and 3 set how early the hearing and the sight are affected. The eye views follow retinitis pigmentosa.
Rod-cone dystrophy
The late road of the RP pattern
The late course of the retinitis pigmentosa pattern: the rods are mostly gone, the field is a small central island, and the cones inside that island begin to fail too.
Late: a central island of around 10 to 15 degrees, dim and low in contrast.
End stage: light and the brightest shapes. Many people keep this much.
Rod-cone dystrophy is the general name for the RP pattern; many genes cause it.
Choroideremia
Scalloped patches, then islands
Night vision goes early; then patches of the mid-field drop out with scalloped edges and merge into a ring. The center is often kept until late, and islands of sight can remain at the far edge.
Early: scattered patches in the middle distance, usually noticed first at night.
Mid: the patches have joined into a ring; the center and an island or two remain.
Late: a central island, sometimes with a last island at the edge, and detail begins to fade.
X-linked; mostly affects males. The ragged edges follow the retina’s atrophy, which is uneven.
Watch Choroideremia progress. (laneId) => `Full sight to ${VIDEO_END_STAGES[laneId]} stage in about 10 seconds. The real course takes years, and many people never reach the last frame.`
Stargardt disease
The center goes, the edges stay
The macula is affected, so the center of view, where detail lives, drops out and is filled with a blur of whatever surrounds it. The edges stay, so walking the path is possible while reading a sign or a face is not.
Early: a small central blur, about the size of a face across a room; reading gets harder first.
Mid: the patch is about 10 degrees across, enough to hide a face at arm’s length.
Late: the patch is 15 degrees or more and the surrounding sight is softer, because the edge of the retina was never built for detail.
ABCA4-related macular dystrophy. People learn to look slightly to one side of what they want to see, so the blind patch moves with the eyes.
Watch Stargardt disease progress. (laneId) => `Full sight to ${VIDEO_END_STAGES[laneId]} stage in about 10 seconds. The real course takes years, and many people never reach the last frame.`
Best disease
The center bends and blurs
Fluid and deposits under the macula lift the retina, so straight lines bend and the center blurs while the edges stay untouched. Reading and faces are affected first.
Early: a yolk-like deposit sits under the center of the retina; sight is often still good, which is why this stage is easy to miss.
Mid: the deposit breaks down and the center blurs and bends.
Late: new blood vessels under the macula can leak or bleed, and the central blur widens.
Best vitelliform macular dystrophy, BEST1. The bending is often the first thing people notice, on door frames and lines of text.
Watch Best disease progress. (laneId) => `Full sight to ${VIDEO_END_STAGES[laneId]} stage in about 10 seconds. The real course takes years, and many people never reach the last frame.`
Cone dystrophy
Detail and color fade, light hurts
Cones carry color, fine detail and comfort in bright light, and they are densest at the center. As they fail, color drains, the center softens and daylight glares; dim light can be easier than bright.
Early: a soft center and faded color; bright days are tiring.
Mid: central detail around 20/200; colors are hard to tell apart.
Late: a broad central blur and little color.
Dim light, mid stage: many people with cone dystrophy see more comfortably in low light, the reverse of the rod conditions.
Cone and cone-rod dystrophies; many genes. In cone-rod forms the rods follow later, so night vision and the outer field join the loss in time.
Watch Cone dystrophy progress. (laneId) => `Full sight to ${VIDEO_END_STAGES[laneId]} stage in about 10 seconds. The real course takes years, and many people never reach the last frame.`
Achromatopsia
No color, daylight glare, soft detail
Present from birth and usually stable: no color at all, detail around 20/200, and daylight so bright it washes the scene out. Many people also have nystagmus, a small constant eye movement, shown here as a slight sideways smear.
Daylight: no color, soft detail and glare.
Bright sun: the scene washes out almost completely. This is the day blindness people describe.
Dusk: the clearest the world gets.
Dark red or amber glasses and dim rooms help; evening is often the clearest time of day.
Leber congenital amaurosis
Severe loss from infancy
Severe loss from infancy that is largely stable rather than progressive. Light, bright shapes and movement may be seen; faces and detail are not. Glare and nystagmus are common. How much sight a person has depends on the gene, so these three views are a range, not a sequence.
Around 20/400: large shapes and the brightest areas, heavily blurred, with little color.
Light perception: light and dark, and the direction light comes from.
No light perception: about one in three people with LCA.
RPE65-related disease is the form the first approved gene therapy treats.
Scene: one computer-rendered park, edited frame by frame from a single base image so every view lines up. Each view is labeled by what it shows, never by a person.
Compare the conditions
What usually goes first, and what tends to stay. Every row is sourced; your own condition page has the detail.
Retinitis pigmentosa. What usually changes first: Night vision, usually from childhood. Center: Often kept for years. Edges: Narrow over time. Night: Lost early. Color: Usually kept until late.
Usher syndrome. What usually changes first: Hearing, then night vision (the RP pattern). Center: Often kept for years. Edges: Narrow over time. Night: Lost early. Color: Usually kept until late.
Choroideremia. What usually changes first: Night vision, then patches of side vision. Center: Kept until late. Edges: Patchy loss. Night: Lost early. Color: Usually kept.
Stargardt disease. What usually changes first: Central detail: reading, faces. Center: Lost. Edges: Kept. Night: Usually kept. Color: Can fade.
Best disease. What usually changes first: Central vision blurs or distorts. Center: Blurred, distorted. Edges: Kept. Night: Usually kept. Color: Usually kept.
Cone dystrophy. What usually changes first: Detail, color and comfort in bright light. Center: Blurred. Edges: Kept, then narrows in cone-rod forms. Night: Kept, then lost. Color: Fades.
Achromatopsia. What usually changes first: Present from birth: color absent, bright light painful. Center: Reduced detail. Edges: Kept. Night: Kept. Color: Absent.
Leber congenital amaurosis. What usually changes first: Severe loss from infancy. Center: Severely reduced. Edges: Severely reduced. Night: Lost. Color: Varies.
Sources: National Eye Institute and MedlinePlus Genetics condition pages, listed at the end.
How to read these
They show a pattern, not a person
Real vision loss is uneven, changes with light, and differs between the two eyes. The views here are the textbook shape of each condition.
The brain fills gaps
People don't see a black hole or a black ring; the missing part is simply not there, the way you don't see your own blind spot. We darken lost field so you can see where it is, and fill a central blind spot with a blur of its surroundings, which is close to what people describe.
Stages take years
Early, mid and late are decades apart for many people, and some never reach the last one. The two conditions present from birth do not move along a track at all.
For the detail, go to the condition
Genes, inheritance, what to expect and what is in trials live on each condition's page in the disease database.
Medical disclaimer. These views are educational approximations. They are not a diagnosis and not a prediction of anyone's vision. Talk with your retina specialist about what your condition means for you.
Sources
National Eye Institute, Retinitis Pigmentosa (loss of night vision as the most common early symptom; loss of side vision).
MedlinePlus Genetics: Usher syndrome; Stargardt macular degeneration; Choroideremia; Cone-rod dystrophy; Achromatopsia; Best vitelliform macular dystrophy; Leber congenital amaurosis.
U.S. Social Security Administration, statutory blindness: central visual acuity of 20/200 or less in the better eye with correction, or a visual field 20 degrees or less at its widest diameter (the "mid" retinitis pigmentosa view is drawn at about 20 degrees).
Zur D, Ullman S. Filling-in of retinal scotomas. Vision Research 2003;43:971–982; and Pratt JD, Ohara JM, Woo SY, Bedell HE. Fixation locus in patients with bilateral central scotomas for targets that perceptually fill in. Optometry and Vision Science 2014;91(3):312–321 (why a blind spot is filled with its surroundings rather than seen as black).