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What does choroideremia look like?

What your son sees as the patches grow. In the words of people who live with it, with the frames from our simulator and the sources behind every statement.

An educational resource for families and clinicians, not a substitute for advice from your eye care team or for medical journals, textbooks and clinical training. Sources are listed at the end of the page. About this page · Updated

Step through the stagesCommon questions
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.
Full sight
A ragged dark ring around a clear center, with small clear islands near the edges.
Choroideremia, mid
The same scene, with sight taken away. An approximation, not a prediction.See early and late

The short answer

A boy with choroideremia sees the world in three phases. First, from childhood, the dark is hard: dim rooms and dusk give him trouble while daytime looks normal. Then, from the teens or twenties, pieces of his side vision go missing in sharp-edged patches that slowly join into a ring around a clear center. Finally, usually decades later, the clear center shrinks to a tunnel. Throughout, what is lost is not black; it is simply absent. Central sharpness is usually kept until middle age or later.

  • What the person is experiencingChoroideremia (CHM) mainly affects boys and men and is caused by changes in a single gene on the X chromosome, passed down through mothers who are usually unaffected carriers.
  • Why the patches have hard edgesChoroideremia looks different from retinitis pigmentosa, and the difference matters for how it feels.
  • In their wordsPublished first-person accounts specific to choroideremia are scarce, and we have not quoted any here; the patient organizations describe the experience in general terms.

See it, stage by stage

The left view never changes. The right one is the same park as choroideremia shows it, drawn from the research our simulator rests on. Pick a stage; the caption tells you what each frame shows and what it cannot.

StageStages take years
Full sight
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.
Choroideremia · Mid
A ragged dark ring around a clear center, with small clear islands near the edges.

Mid

A scalloped ring of patches that has joined up around a clear center, with the lost areas drawn as absence rather than black.

Mid: the patches have joined into a ring; the center and an island or two remain.

Watch choroideremia progress

Full sight to mid stage in about 10 seconds. The real course takes years, and many people never reach the last frame.

No sound. The video does not start on its own.

Open the full simulator, all ten conditionsHow these frames were built

What the person is experiencing

Choroideremia (CHM) mainly affects boys and men and is caused by changes in a single gene on the X chromosome, passed down through mothers who are usually unaffected carriers 1. The first symptom is usually night blindness, which often appears in childhood or early adulthood 2. This is followed by loss of vision in the mid-periphery, which can begin in the late teens or twenties 2. Doctors describe these blind spots as forming "an irregular ring, leaving only patches of peripheral vision while central vision remains intact", and the loss then spreads in both directions, eventually leading to tunnel vision in the thirties or forties 2.

Central vision is spared for a long time. Good sharpness is generally kept until the fifth to seventh decade, though color vision can fade before sharpness does 1. Even in advanced disease, small islands of vision can remain at the very center and light can still be seen far out to the sides 1. Other changes can include reduced sharpness, poorer depth perception that makes distances harder to judge, color changes, more glare, and worsening night blindness 2.

Why the patches have hard edges

Choroideremia looks different from retinitis pigmentosa, and the difference matters for how it feels. In RP the edges of the lost field are gradual. In choroideremia the retina is lost in sharply bounded patches, and researchers who tested vision right at the edge of these patches found that sight drops off abruptly: full sensitivity on one side and a dense blind area on the other, over a distance smaller than a standard test spot 3. For your son this means a face or a cup can be fully visible and then, with a small movement of the eyes, partly gone. Because the patches sit in the mid-periphery, not the center, he usually does not notice them directly; what he notices is that things appear "from nowhere" on one side.

In their words

Published first-person accounts specific to choroideremia are scarce, and we have not quoted any here; the patient organizations describe the experience in general terms. The Choroideremia Research Foundation describes vision "leading to tunnel vision" and a "washed-out appearance" in later stages 4. The pattern of night blindness followed by side-vision loss is shared with RP, so the RP accounts on this site apply: not noticing the early loss, the brain filling in the gaps, and objects that pop up unseen from the side 5 6 7.

What our simulation shows

The hard edges on the patches are deliberate and come from the edge study above 3.

The scene with scattered dark patches with ragged edges in the mid-field.
EarlyA few sharp-edged patches of loss in the mid-periphery with a clear center.
A ragged dark ring around a clear center, with small clear islands near the edges.
MidA scalloped ring of patches that has joined up around a clear center, with the lost areas drawn as absence rather than black.
A small clear center in dark.
LateThis frame leaves only a small central island with a hint of light at the far edges, as the clinical literature describes 8 1.

Signs you might notice in a boy

  • Trouble at dusk, in cinemas and in dark hallways from an early age, with normal daytime vision 2 9.
  • Bumping into things on one side, or missing a ball that comes from one direction, before he reports anything wrong 10 11.
  • Misjudging distances, for example on steps or when reaching 2.
  • A mother or sister with mild night blindness, which carriers can have 1.

Common questions

Will he go blind?

Choroideremia is progressive and can ultimately lead to very severe loss, but the rate varies between individuals, severe impairment commonly occurs in late adulthood, and some people keep useful vision well into later life 12 2. Even late in the disease, central islands and far-peripheral light perception often remain 1.

Is it the same as RP?

It follows a similar order (night first, then sides, then center) but the patches have sharper edges and the gene and inheritance are different 3 1.

What helps right now?

Lighting on stairs and hallways, a flashlight, telling teachers and coaches which side is weaker, and genetic confirmation, which is what opens the door to clinical trials 1.

Go deeper

References

Sources were read on Oct 22-23, 2026.

  1. 1.American Academy of Ophthalmology, EyeWiki. Choroideremia. https://eyewiki.aao.org/Choroideremia
  2. 2.Choroideremia Research Foundation (CureCHM). Symptoms and Progression. https://curechm.org/symptoms-progression/
  3. 3.Tuten WS, Vergilio GK, Young GJ, Bennett J, Maguire AM, Aleman TS, et al. Visual function at the atrophic border in choroideremia assessed with adaptive optics microperimetry. Ophthalmol Retina. 2019;3(10):888-899. doi:10.1016/j.oret.2019.05.002 https://pmc.ncbi.nlm.nih.gov/articles/PMC6778501/
  4. 4.Choroideremia Research Foundation (CureCHM). What is Choroideremia. https://www.curechm.org/what-is-choroideremia/
  5. 5.GeneReviews [Internet]. Nonsyndromic Retinitis Pigmentosa Overview. University of Washington, Seattle. https://www.ncbi.nlm.nih.gov/books/NBK1417/
  6. 6.Hadley. Hadley Presents: The Blind Poet, Dave Steele (podcast transcript; Dave Steele describing retinitis pigmentosa). https://hadleyhelps.org/podcasts/hadley-presents/blind-poet-dave-steele
  7. 7.Lawson Visconti L. Going blind in a sighted world (personal blog; first-person account of retinitis pigmentosa). http://lauralawsonvisconti.com/blog/rp
  8. 8.A Race Against Blindness. How our vision simulations were built: research basis and rendering conventions (Education Hub, Oct 2026). https://araceagainstblindness.org/education/vision-simulations/methodology
  9. 9.Nemours KidsHealth. Retinitis Pigmentosa (for Parents). https://kidshealth.org/en/parents/retinitis-pigmentosa.html
  10. 10.Gene Vision (UK). Retinitis pigmentosa: for patients. https://gene.vision/knowledge-base/retinitis-pigmentosa-for-patients/
  11. 11.A Race Against Blindness. Children and Families Guide: Early Warning Signs by Age. https://araceagainstblindness.org/education/children-and-families
  12. 12.Retina UK. Choroideremia. https://retinauk.org.uk/information-and-support/about-inherited-sight-loss/types-of-inherited-sight-loss/choroideremia/

About this page

This page is an additional resource for the community. It is not a substitute for advice from your own eye care team, or for medical journals, textbooks or clinical training. We have done our best to provide accurate and up-to-date information, and the references are listed above, but inaccuracies and omissions may exist. Confirm any medical information with your eye care team or against primary-source medical education resources before relying on it. The simulation frames are approximations built from the cited literature, not a prediction of anyone's vision.