Cataract Vision Simulator by Type

Cataract vision by day

Normal vision

The drive as filmed: sharp edges, full contrast and true colour.

Nuclear

The centre of the lens hardens and browns, so colour shifts towards yellow and fine detail goes evenly — the road sign is the first thing to become unreadable.

Cortical

Wedge-shaped opacities at the rim of the lens scatter light, so bright areas veil whatever sits beside them while colour stays closer to true.

Posterior subcapsular

A plaque sits on the visual axis, so the middle of the view fills with a bright veil, and bright light closes the pupil onto it and makes it worse.

Cataract vision at night

Normal vision

The same drive at night as filmed: street lamps and traffic lights stay small and separate.

Nuclear

Every light softens into a warm blur and the yellowing takes what is left of the contrast.

Cortical

Small bright lights can streak into spokes, while the darker parts of the scene keep their detail.

Posterior subcapsular

Headlights and street lamps flare into glare across the centre of the view.

Cataracts and colour, up close

Normal vision

A face at arm’s length as filmed: white stays white, and the fur and the whiskers hold their edges.

Nuclear

A white coat turns cream and blue eyes go grey. A known white is where the colour shift gives itself away, which is why this is the view it shows on.

Cortical

The lit side of the face veils whatever sits beside it while colour stays close to true. Indoors there is nothing small and hard enough to throw spokes — that is the night view’s half.

Posterior subcapsular

The middle of the view fills with a bright veil, so the face is the part that goes, and good light makes it worse rather than better.

Cataract vision indoors, in good light

Normal vision

A clinic reception as filmed: the lettering on the wall is readable and each downlight stays a point.

Nuclear

Fine detail goes evenly and the room turns warm. The lettering on the far wall is the first thing to become unreadable.

Cortical

Light off the white walls veils the lettering beside it, while the doors and the tree keep their colour.

Posterior subcapsular

A bright veil sits over the middle of the room, so the lettering on the far wall goes first.