Cataract IOL Vision Range Explorer

1) Choose the cataract-eye plan

Right-eye lens type RayOne EMV

Lens type changes the modeled depth of focus and trade-offs, not the eye’s target prescription.

Right-eye post-op target −1.50 D

More negative = clearer closer without glasses, but less distance vision. Doctor’s discussed range was roughly −1.25 to −1.50.

Left-eye natural accommodation 3.00 D

This represents how much the non-cataract eye can still focus closer when corrected. Younger eyes may have more; presbyopic eyes have less.

Depth-of-field tolerance Normal

Higher = more forgiving. Real-life depth of field depends on pupil size, lighting, contrast, astigmatism, cornea, and brain adaptation.

These are starting points, not recommendations.

2) Add glasses / correction

Use glasses in the model

When off, both eyes are modeled without glasses. When on, each glasses lens power is adjustable.

Right glasses lens 0.00 D

Left glasses lens 0.00 D

Lens-to-eye distance 12 mm

Typical glasses sit around 10–14 mm from the eye. Set to 0 mm to approximate contact-lens-like correction, which greatly reduces spectacle image-size mismatch.

“Computer” leaves about −1.50 D residual. “Near” leaves about −3.00 D residual. Presets now keep tracking the right-eye target when you adjust the cataract-eye plan.

Right residual focus

−1.50 D

without glasses

Left residual focus

−5.50 D

left baseline fixed at −5.50 D

Glasses lens gap

0.00 D

no spectacle imbalance

Image-size gap

spectacle-induced estimate

Best functional range

—

where at least one eye is modeled clear

Estimated image-size disparity

Right cataract/IOL eye

100.0% image size

Left natural eye

100.0% image size

Relative image size

0.0%

right image compared with left

Left looks largerRight looks larger

Low estimated mismatch

This uses a simple spectacle-magnification estimate from lens power and vertex distance. If a glasses preset is selected, the right lens tracks the cataract-eye target in real time.

Clear vision range

Right cataract/IOL eye

Left natural eye

Overlap: both eyes clear at same distance

Functional: at least one eye clear

RayOne EMV / “monofocal-plus”

How to read this

Diopters map to distance: a −1.50 D eye focuses around 1 ÷ 1.50 = 0.67 m, before accounting for depth of field. A −3.00 D eye focuses around 33 cm.

Glasses power: a −5.50 D glasses lens fully corrects a −5.50 D eye for distance. Adding plus / reducing minus shifts the clear range closer.

Image-size disparity: minus spectacle lenses minify and plus spectacle lenses magnify. A larger lens-power difference, especially with glasses sitting farther from the eye, can make one eye’s image look bigger than the other.

Astigmatism: this assumes the right-eye astigmatism is corrected by a toric IOL or glasses. Uncorrected astigmatism can blur all ranges.

Important: the chart is a teaching tool. Real vision also depends on IOL power accuracy, pupil size, dry eye, retina, cornea, contrast, neuro-adaptation, and surgeon measurements.