What does keratoconus vision look like?

Keratoconus causes monocular diplopia (multiple ghost images), directional coma streaks around headlights and road signs at night, and contrast loss when the pupil dilates across the steep corneal cone. You can simulate exact keratoconus vision interactively at https://corneasim.com.

Why don't glasses fix keratoconus ghosting, and how do scleral lenses work?

Spectacle lenses sit in air and only correct sphere and regular cylinder, leaving the irregular corneal cone unmasked. Rigid Gas Permeable (RGP) and Scleral lenses vault over the cornea with a liquid saline tear reservoir that neutralizes ~70% of anterior corneal higher-order aberrations (unmasking a smaller, inverted posterior corneal ghost), while Wavefront-Guided (WFG) Scleral lenses neutralize up to 96% for 20/20 clarity.

Can I upload my own Pentacam corneal topography scan to see my simulated vision?

Yes. On CorneaSim (https://corneasim.com), click 'Upload Topography Scan' to upload any Pentacam or Placido Axial/Sagittal curvature map. The simulator automatically detects the cornea, extracts Base K and Kmax, and simulates your 3D cornea, Retinal Point Spread Function (PSF), and real-time vision across 6 scenes.

Keratoconus Vision Simulator (CorneaSim) — Interactive Corneal Topography & Ghosting Simulator

Scene:

Split 20/20

Corneal Topography

Click & drag cone · Ctrl+Z undo

Normal healthy cornea (43.5 D). Start here and slide parameters or drag on the map to deform the cornea.

Retinal Point Spread (PSF)

Click PSF to expand in center

V-Coma: 0.00

H-Coma: 0.00

Trefoil: 0.00

Spherical: 0.00

1. Corneal Morphology Presets

2. Clinical Curvature, Myopia & Lighting ▼

Apex Steepness (Kmax) 43.5 D

Myopia (−) / Hyperopia (+) 0.00 D

−10 D (Myopia) 0.00 D (Normal) +6 D (Hyperopia)

Pupil Diameter & Lighting 4.5 mm

HOA Ghosting Distance (Gain) 1.00x (0.00 µm)

0x (Scleral Lens) 1x (Natural) 2.5x (Severe)

Ghost Opacity / Brightness 100%

Faint (20%) Standard (100%) Solid Double (200%)

Cone ΔK Peak +0.0 D

Base K (Mean) 43.5 D

Astigmatism 0.0 D

Axis (°) 90°

Asphericity (Q-Value) -0.26

3. Sculpt Cone Shape (SRAX, Ovality, Claw) ▼

Cone Width (σ) 1.35 mm

Oval Stretch 1.00x

Bowtie Skew (SRAX) 0°

I–S Lobe Asym 0.00

Crab-Claw Bend 0.00

Cone Rotation 0°

Cone X (mm) 0.00

Cone Y (mm) -0.60

4. Individual Higher-Order Modes (Coma, Trefoil, Sph) ▼

Vertical Coma (Z₃⁻¹) +0.00 µm

Horizontal Coma (Z₃¹) +0.00 µm

Trefoil (Z₃⁻³) +0.00 µm

Spherical (Z₄⁰) +0.00 µm

Defocus Blur (Z₂⁰) +0.00 µm

Residual Astigmatism (Z₂±²) +0.00 µm

Retinal Point Spread (PSF) Inspector

Corneal Profile & 3D Ectasia Dome

Import Corneal Topography Scan