Optics
Myopia corrected
A diverging lens (negative power) moves the far point to infinity, and the distant object snaps into focus.
Myopia corrected — interactive Optics simulation. A diverging lens (negative power) moves the far point to infinity, and the distant object snaps into focus. Free browser-based virtual physics lab with live SI measurements and a guided tutorial.
Myopia correction
A diverging lens (negative power) moves the far point to infinity, and the distant object snaps into focus.
A concave (diverging) spectacle lens spreads rays before they enter the eye, shifting the focal plane backward onto the retina for distant objects. Power is chosen so the far point moves to infinity—the standard correction for myopia.
- Diverging lens
- Far point → ∞
Investigation brief
Plan the question before you open the lab
The brief mirrors the prerendered page: driving question, competing predictions, variable roles, governing laws, setup, analysis and extension prompts remain visible and in this order.
Driving question
A myopic eye's diverging corrective lens (f = −70 cm here) is meant to make distant objects appear to be at the eye's far point instead. Does this work the same way no matter how far away the actual object really is?
Predictions to weigh
- Within the object distances this bench can actually reach, the virtual image distance still varies a lot as the true object distance changes — it hasn't yet settled near the far point.
- Yes — for any sufficiently distant object, the diverging lens forms a virtual image very close to its own focal point (near the far point), regardless of the exact true distance.
- The corrective lens doesn't change the effective image distance at all.
Variable roles
What you set:
- True object distance d_o (cm)
What you measure:
- Corrective lens's image distance d_i (cm)
How the investigation runs
- Open the myopia-corrected preset and press Reset. The corrective diverging lens has f = −70 cm, matching this eye's far point.
- Enable the corrective lens's image-distance readout.
- Set the true object distance for each trial (all reasonably far) and record the virtual image distance formed by the corrective lens.
Governing equation
How Corrective Lenses Redirect Light — dᵢ = dₒ·f/(dₒ − f)
A diverging corrective lens with f equal to (the negative of) the eye's far point images a TRULY distant object — many hundreds of cm away, well beyond what a tabletop bench can reach — at (or very near) that far point, exactly where the myopic eye CAN still focus. Closer than that, as this lab sheet's own trials show, the image still shifts noticeably with object distance.
What the printable worksheet asks students to work out
- For one trial, compute d_i from 1/f = 1/d_o + 1/d_i using f = −70 cm. Compare to the table.
- Your table shows d_i still changing substantially even at the largest object distance this bench can reach (d_o = 100 cm, d_i only 58.8% of the way to f = −70 cm). Using 1/f = 1/d_o + 1/d_i, explain why d_i needs d_o in the many hundreds of cm before it gets truly close to f — this correction genuinely only becomes near-perfect for objects much farther away than this bench can place them, not for every 'distant' object.
Where this shows up beyond the lab
- This is the actual mechanism behind corrective lenses: they don't change what the eye's own lens does — they pre-process the light so the eye 'sees' the corrected image at a distance it CAN already focus on. Explain why this means corrective lenses work WITH the eye's own optics rather than replacing them.
- Compare this experiment's fixed f = −70 cm to the myopia experiment's corrective-power calculation for far point = 70 cm (P = −100/70 ≈ −1.43 D, so f = 1/P ≈ −70 cm). Confirm these are the same lens, described two different ways (focal length vs. diopters).
- AP Physics 2 — Unit 13: Geometric Optics
- General High School Physics — Light & optics
- NGSS High School Physics — Wave properties
- Welcome to Myopia Corrected
- Select the corrective lens
- Press Play
- Diverging correction
- Open the Properties panel
- You did it!
Open the interactive simulation to build the scene, press Play, and explore with live measurements and a guided tutorial.