Section 252 of 440
Complete canonical tutorial. This reader section contains the same teaching body as PWR-069 · Depth perception. Open the Power dossier.
PWR-069 · SELF GUIDED full tutorial
Name which object looks nearer and identify the cue that created the judgment
Stereopsis can sometimes be recovered in selected adults, but depth perception is larger than binocular disparity. Depth perception uses binocular disparity, motion, overlap, size, perspective and other cues. The safe fixture teaches cue analysis in flat images: choose the nearer object, name the cue, check the key and compare a cue-conflict image. It does not measure stereopsis or justify driving claims. The learner verifies cue use by predicting what would happen if overlap, relative size or perspective were removed from the image, which makes the depth judgment explainable rather than intuitive.
1 · Permission and limits
Know exactly what you may do
2 · Get ready
Gather what you need and check the starting conditions
What you need
- An exact A5-card construction sheet. Set A: A1 draw a 4 cm red square covering the left 1 cm of a 4 cm blue circle (red nearer; overlap); A2 reverse which shape covers the other (blue nearer; overlap); A3 draw two otherwise identical black circles, 4 cm and 2 cm diameter (larger circle intended nearer; relative size); A4 draw two rails 12 cm apart at the bottom converging to 3 cm apart at the top and place identical 1.5 cm squares low and high between them (lower square intended nearer; linear perspective); A5 use a 2 cm red square that covers a 1 cm edge of a 5 cm blue circle (overlap says red nearer while relative size says red farther; cue conflict). Set B repeats those five structures with triangle/hexagon shapes, left/right positions exchanged and new colours.
- A folded key naming the relations above plus two cue-removal companions: A1-crop hides the overlap edge while preserving visible areas of both shapes, and A4-crop hides the converging rail edges. The learner predicts stay, weaken or reverse before each companion is shown. A separate unscored shadow example shows two identical balls, one with an attached ground shadow and one with its shadow displaced, solely to learn the shadow label; it has no keyed near/far answer.
- Fixed display/print size, distance, lighting and ordinary correction.
- Trial sheet for answer, cue, confidence and symptoms.
Before you start
- Use images only; no stairs, catching, pouring or real distance judgement is tested.
- Keep screen/print size, distance and correction fixed.
- Define the allowed cue labels with examples.
- New double vision, eye misalignment or sudden depth difficulty needs professional assessment.
3 · The method
Follow these steps in order
- Learn the cue labels
Review overlap, relative size, perspective and shadow with one obvious example each.
Why: Naming the cue separates reasoning from a vague depth feeling.
Check: The learner matches all four cue labels to examples.
- Lock the image setup
Record device/print, image size, distance, lighting and correction.
Why: Scaling and viewing conditions can alter pictorial cues.
Check: The same setup can be reproduced.
- Choose nearer before checking
For one image, state which named object appears nearer.
Why: A committed relation is needed before explanation or feedback.
Check: One near/far answer is recorded.
- Name the supporting cue
State the visible feature used, such as one shape blocking another or converging lines.
Why: A correct answer for the wrong reason may not transfer.
Check: The answer includes one observable cue.
- Reveal and compare
Check both relation and cue against the key, preserving the original response.
Why: Feedback should correct the specific inference, not only mark right/wrong.
Check: The missed cue is named on every error.
- Use a cue-conflict image
Compare an image where size and overlap suggest different relations and state which cue you trust and why.
Why: Conflicts reveal that depth is constructed from multiple signals.
Check: The learner identifies the conflict rather than forcing certainty.
- Retest novel scenes
After a delay, classify unfamiliar scenes with the same cue labels and no feedback first.
Why: Novel images test the cue method rather than picture memory.
Check: No baseline image appears in the retest.
- Run a cue-removal check
For one answered image, cover or crop the feature named as the main cue without changing the objects themselves. Predict whether the near–far answer should stay, weaken or reverse, then inspect the edited companion image.
Why: If the judgment survives removal of the claimed cue unchanged, another cue may actually be driving the answer.
Check: The learner predicts the effect before viewing the companion and can name the cue that remains after the edit.
4 · Worked example
See the whole method used once
Scenario
Lin compares drawings of two boxes using overlap and perspective.
Walkthrough
- Lin reviews the four cue labels and fixes the tablet at 60 cm.
- In image one, box A overlaps box B, so Lin selects A as nearer and names overlap.
- In a conflict image, A is smaller but overlaps B; Lin records both cues and lower confidence.
- After checking the key, Lin preserves the original answer and writes which cue dominated.
- Two days later Lin uses new room scenes before feedback.
- Lin predicts that hiding the overlap edge will reduce certainty; in the companion image, relative size remains and Lin records that the answer now depends on size rather than overlap.
Result
Lin improves at explaining pictorial depth relations. This does not show stereoacuity or reliable real-world distance estimation. Lin now demonstrates not only a correct relation but a falsifiable explanation of which flat-image cue produced it.
5 · Right and wrong
Compare correct or safer execution with the common wrong version
| Moment | Right / safer | Wrong / riskier | Why it matters |
|---|---|---|---|
| Cue | Name the visible overlap, size, perspective or shadow evidence. | Answer “it just looks closer”. | Cue naming makes the method checkable. |
| Conflict | Record competing cues and lower confidence. | Force a certain answer while ignoring conflict. | Depth cues can disagree. |
| Setup | Keep image scale and distance fixed. | Zoom difficult pictures. | Zoom changes relative visual size. |
| Retest | Use unfamiliar scenes. | Repeat the same drawings until memorised. | Picture memory is not cue transfer. |
| Claim | Call it pictorial-cue reasoning. | Call it stereopsis recovery. | Flat-image cues do not measure binocular disparity. |
| Testing the explanation | Remove the named pictorial cue and predict the changed judgment. | Accept a cue label because it sounds plausible without manipulating the image. | A cue-removal comparison checks whether that visible feature actually carried the decision. |
6 · Common mistakes
Spot the error and apply the correction
| Mistake | Fix |
|---|---|
| Answer “it just looks closer”. | Name the visible overlap, size, perspective or shadow evidence. |
| Force a certain answer while ignoring conflict. | Record competing cues and lower confidence. |
| Zoom difficult pictures. | Keep image scale and distance fixed. |
| Repeat the same drawings until memorised. | Use unfamiliar scenes. |
| Call it stereopsis recovery. | Call it pictorial-cue reasoning. |
| The learner names several cues after seeing the key, so no cue could have been wrong. | Commit one primary cue and one backup cue before checking, then test the primary cue with a cropped companion. |
7 · Practice
Turn the steps into a usable skill
First session
- Construct or have a helper construct A1–A5, B1–B5, A1-crop and A4-crop from the stated centimetre measurements and fold the relation key.
- Review one overlap, relative-size, perspective and unscored shadow example, then lock print/display size, 60 cm distance, lighting and correction.
- Classify A1–A5, naming nearer object, primary cue, backup cue and confidence before checking the key; A5 must be marked conflict rather than forced certainty.
- Predict stay, weaken or reverse for A1-crop and A4-crop before revealing each companion and record which cue remains.
- After at least 48 hours, classify concealed B1–B5 under the same setup before feedback.
Repeat plan
Use one 10–15-image set once or twice weekly. Progress from single-cue to cue-conflict images, then novel scenes; clinical binocular treatment stays with eye professionals.
Progress when
- Near/far accuracy improves on novel images.
- Cue labels match visible features.
- Confidence falls appropriately when cues conflict.
Do not progress when
- Double vision, nausea or eye strain appears.
- Image scale or correction changes.
- The learner uses the fixture for stairs, driving or clinical claims.
8 · Check the result
Measure what changed
Correct near/far relation, cue label and cue-conflict recognition on the supplied flat-image cards
How: Record correct near/far relation, correct cue identification, cue conflicts, confidence, image setup and symptoms. Count whether cue-removal predictions correctly anticipate unchanged, weaker or reversed judgments.
Good result: A novel set shows better relation and cue accuracy, including correct recognition of conflicts, without symptoms.
This does not prove: Report stereoacuity/disparity threshold and task, plus monocular cues and functional configuration; stereoacuity cannot diagnose or summarise all depth perception.
Self-check
- Can you demonstrate “Lock the image setup”? The same setup can be reproduced.
- Can you demonstrate “Name the supporting cue”? The answer includes one observable cue.
- Can you demonstrate “Retest novel scenes”? No baseline image appears in the retest.
- If your named overlap cue is covered, can you predict which remaining cue should control the near–far answer?
9 · Stop, adapt or get help
Keep the safety boundary practical
Stop and get help
- Seek urgent assessment for sudden double vision, eye movement change, severe headache or acute neurological symptoms.
- Stop for eye strain, nausea, dizziness or persistent blur.
- Use an eye professional for suspected stereopsis or binocular-vision problems.
Accessibility and adaptations
- Use high-contrast, simplified images while retaining the same cue.
- Allow spoken, pointing or switch answers without time pressure.
- Describe non-target image content aloud while leaving the tested depth cue for the learner to judge.
10 · Evidence and limits
Why these instructions are here
- primary research
Primary research reports stereopsis recovery in selected adults with abnormal binocular vision under controlled training.
Recovery of stereopsis through perceptual learning in human adults with abnormal binocular vision - primary research
A controlled amblyopia treatment trial supports clinical specificity and does not validate a flat-image home task as treatment.
Randomised trial of three treatments for amblyopia: Vision therapy and patching, perceptual learning and patching alone
Limits
- Report stereoacuity/disparity threshold and task, plus monocular cues and functional configuration; stereoacuity cannot diagnose or summarise all depth perception.
- Unsupported claim: Unlock 3D vision for everyone.
- Unsupported claim: Depth perception is one stereo score.
- Unsupported claim: Patching yourself retrains both eyes.
- Pictorial cue analysis does not measure stereoacuity, diagnose binocular disorder or prove safe real-world distance judgement.
Open the complete canonical research register
- Primary empirical supportLimiting / contraryRecovery of stereopsis through perceptual learning in human adults with abnormal binocular vision
J. Ding; D. M. Levi · 2011 · Primary research
- Primary empirical supportLimiting / contraryRandomised trial of three treatments for amblyopia: Vision therapy and patching, perceptual learning and patching alone
R. Hernández-Andrés; M. Á. Serrano; A. Alacreu-Crespo; M. J. Luque · 2025 · Primary research
Read the complete evidence interpretation on the Power dossier.
Tutorial delivery controls
Learn, adapt, troubleshoot and resume
Progress is saved only in this browser on this device.
Step-by-step learner mode
Each activity includes its success check, a nearby accessible alternative and an “I’m stuck” correction path. Alternatives preserve the target where possible; when they change the task, Titan labels them as related rather than equivalent.
Learn the cue labels
Review overlap, relative size, perspective and shadow with one obvious example each.
Naming the cue separates reasoning from a vague depth feeling.
The learner matches all four cue labels to examples.
I’m stuck on this step
Reset: Re-read this authored instruction — “Review overlap, relative size, perspective and shadow with one obvious example each.” — and its success check, then attempt only this step.
Possible snag: Answer “it just looks closer”.
Correction: Name the visible overlap, size, perspective or shadow evidence.
Stop / get help: Seek urgent assessment for sudden double vision, eye movement change, severe headache or acute neurological symptoms.
Lock the image setup
Record device/print, image size, distance, lighting and correction.
Scaling and viewing conditions can alter pictorial cues.
The same setup can be reproduced.
I’m stuck on this step
Reset: Re-read this authored instruction — “Record device/print, image size, distance, lighting and correction.” — and its success check, then attempt only this step.
Possible snag: Force a certain answer while ignoring conflict.
Correction: Record competing cues and lower confidence.
Possible snag: Zoom difficult pictures.
Correction: Keep image scale and distance fixed.
Stop / get help: Seek urgent assessment for sudden double vision, eye movement change, severe headache or acute neurological symptoms.
Choose nearer before checking
For one image, state which named object appears nearer.
A committed relation is needed before explanation or feedback.
One near/far answer is recorded.
I’m stuck on this step
Reset: Re-read this authored instruction — “For one image, state which named object appears nearer.” — and its success check, then attempt only this step.
Possible snag: The learner names several cues after seeing the key, so no cue could have been wrong.
Correction: Commit one primary cue and one backup cue before checking, then test the primary cue with a cropped companion.
Stop / get help: Seek urgent assessment for sudden double vision, eye movement change, severe headache or acute neurological symptoms.
Name the supporting cue
State the visible feature used, such as one shape blocking another or converging lines.
A correct answer for the wrong reason may not transfer.
The answer includes one observable cue.
I’m stuck on this step
Reset: Re-read this authored instruction — “State the visible feature used, such as one shape blocking another or converging lines.” — and its success check, then attempt only this step.
Possible snag: The result from “State the visible feature used, such as one shape blocking another or converging lines.” does not yet meet this declared check: The answer includes one observable cue.
Correction: Return to the start of “Name the supporting cue”, reduce complexity or pace, and repeat only the part needed to satisfy: “The answer includes one observable cue.”
Stop / get help: Seek urgent assessment for sudden double vision, eye movement change, severe headache or acute neurological symptoms.
Reveal and compare
Check both relation and cue against the key, preserving the original response.
Feedback should correct the specific inference, not only mark right/wrong.
The missed cue is named on every error.
I’m stuck on this step
Reset: Re-read this authored instruction — “Check both relation and cue against the key, preserving the original response.” — and its success check, then attempt only this step.
Possible snag: Call it stereopsis recovery.
Correction: Call it pictorial-cue reasoning.
Stop / get help: Seek urgent assessment for sudden double vision, eye movement change, severe headache or acute neurological symptoms.
Use a cue-conflict image
Compare an image where size and overlap suggest different relations and state which cue you trust and why.
Conflicts reveal that depth is constructed from multiple signals.
The learner identifies the conflict rather than forcing certainty.
I’m stuck on this step
Reset: Re-read this authored instruction — “Compare an image where size and overlap suggest different relations and state which cue you trust and why.” — and its success check, then attempt only this step.
Possible snag: The result from “Compare an image where size and overlap suggest different relations and state which cue you trust and why.” does not yet meet this declared check: The learner identifies the conflict rather than forcing certainty.
Correction: Return to the start of “Use a cue-conflict image”, reduce complexity or pace, and repeat only the part needed to satisfy: “The learner identifies the conflict rather than forcing certainty.”
Stop / get help: Seek urgent assessment for sudden double vision, eye movement change, severe headache or acute neurological symptoms.
Retest novel scenes
After a delay, classify unfamiliar scenes with the same cue labels and no feedback first.
Novel images test the cue method rather than picture memory.
No baseline image appears in the retest.
I’m stuck on this step
Reset: Re-read this authored instruction — “After a delay, classify unfamiliar scenes with the same cue labels and no feedback first.” — and its success check, then attempt only this step.
Possible snag: Repeat the same drawings until memorised.
Correction: Use unfamiliar scenes.
Stop / get help: Seek urgent assessment for sudden double vision, eye movement change, severe headache or acute neurological symptoms.
Run a cue-removal check
For one answered image, cover or crop the feature named as the main cue without changing the objects themselves. Predict whether the near–far answer should stay, weaken or reverse, then inspect the edited companion image.
If the judgment survives removal of the claimed cue unchanged, another cue may actually be driving the answer.
The learner predicts the effect before viewing the companion and can name the cue that remains after the edit.
I’m stuck on this step
Reset: Re-read this authored instruction — “For one answered image, cover or crop the feature named as the main cue without changing the objects themselves. Predict whether the near–far answer should stay, weaken or reverse, then inspect the edited companion image.” — and its success check, then attempt only this step.
Possible snag: The result from “For one answered image, cover or crop the feature named as the main cue without changing the objects themselves. Predict whether the near–far answer should stay, weaken or reverse, then inspect the edited companion image.” does not yet meet this declared check: The learner predicts the effect before viewing the companion and can name the cue that remains after the edit.
Correction: Return to the start of “Run a cue-removal check”, reduce complexity or pace, and repeat only the part needed to satisfy: “The learner predicts the effect before viewing the companion and can name the cue that remains after the edit.”
Stop / get help: Seek urgent assessment for sudden double vision, eye movement change, severe headache or acute neurological symptoms.
Correct versus incorrect execution
These accessible process diagrams are built from the tutorial’s own right/wrong teaching. They are not anatomical illustrations and do not add technique beyond the canonical tutorial.
Name the visible overlap, size, perspective or shadow evidence.
Answer “it just looks closer”.
Record competing cues and lower confidence.
Force a certain answer while ignoring conflict.
Keep image scale and distance fixed.
Zoom difficult pictures.
Use unfamiliar scenes.
Repeat the same drawings until memorised.
Call it pictorial-cue reasoning.
Call it stereopsis recovery.
Remove the named pictorial cue and predict the changed judgment.
Accept a cue label because it sounds plausible without manipulating the image.
Method-structure checklist
10 of 10 structural checks present
- Ordered, Power-specific instructions — present
- Every activity has a success check — present
- Materials or supplied records are declared — present
- Measurement or assessment rule is present — present
- Tutorial-specific troubleshooting is present — present
- Stopping or escalation boundary is present — present
- Every activity has an adjacent alternative — present
- Correct-versus-incorrect comparison is present — present
- Evidence context is bound to the Power record — present
- Planning metadata is present — present
The method-readiness band and presence checklist assess tutorial presentation and are separate from evidence quality for the underlying Power. They are automated editorial aids, not human approval.
Manual editorial sign-off: Pending. This tutorial must not display a human-approved state until an identified editor signs the exact content hash.