A fisheye or other distortion view always needs a one-click way back to the plain, undistorted view

What it is

A distortion view must always ship with an "off" exit: one action back to the undistorted plain view, or a strength control that reaches zero. The reasons accumulate from every previous card — distortion corrupts reading, targets drift, comprehension load grows — and users vary in how much these costs bite them; nobody should be locked inside the warp. Distortion is the option; the plain view is the floor.

Why it happens

The exit is necessary because distortion's payoff varies by person and task: on the same map, one inspector thrives on the fisheye while a measurer is dragged down by the warp; the same user wants the fisheye while browsing and linear while reading. A distortion view without an exit imposes one working style on every task. The exit also carries error-recovery and trust duties: when the warp implementation misbehaves, the parameters are tuned wrong, or the user simply cannot adapt, the exit is the damage control; a feature that can be switched off invites trying, and one that cannot invites avoidance from the start. Engineering-wise, "strength zero" and "off" should be equivalent — the ideal form is a continuously adjustable strength slider where off is simply zero.

Where it stops holding

The exit must be instant and lossless: turning the distortion off preserves viewport position and selection, removing only the warp; implementing off as "reset everything" destroys the user's working state and punishes the very act of exiting. The entry point must stay visible while the warp is on (toolbar button, shortcut); an exit buried deep in a menu will hardly ever be used. Paired with the toggle comes memory — the user's distortion preference (on/off/strength) should persist and be restored next time, never re-defaulted to on each session.

Applying it

• Give the distortion feature a persistent toggle and strength slider at a fixed position, with shortcut access.
• On disabling, keep the viewport, selection, and filters; remove only the warp.
• Persist the user's distortion preference across sessions.
• Verification: watch the real-world trigger rate of "disable distortion"; if users keep working in that view afterwards (rather than fleeing), the toggle is doing its job — they simply switched to the form their current task needs.

Related

• Same group: U6.07.1 Fisheye achieves focus plus context by local magnification and peripheral compression · U6.07.2 Geometric distortion breaks positional encoding; magnitudes stop being readable · U6.07.3 Distortion shifts as the focus moves; targets drift and become hard to hit · U6.07.4 Distortion views suit navigation and location, not reading or comparison
• Nearby: U6.04.3 Zooming must keep an exit back to the global view · U6.02.3 The scope of linkage needs to be controllable
• Search terms: distortion toggle · fallback view · progressive enhancement