How to Improve Lighting for a Customer With Low Vision

Why this matters

"Brighter" is the request, and brighter alone often makes it worse. An older eye needs more light, and it is also far more sensitive to glare, slower to adapt between bright and dark, and easily blinded by the very fixture installed to help it. The shop that swaps every bulb for the highest-output lamp on the shelf leaves a customer squinting under a ceiling light while she still cannot read the stove dial, and still walks to the bathroom at night in the dark because the overhead light is too harsh to turn on. Good lighting for low vision is mostly placement, shielding and control.

What has changed in the eye

You do not need to diagnose anything, and should not; the person or their eye care provider will tell you what they have. You do need to know what it does to light.

• The aging eye has a smaller pupil and a yellowed, cloudier lens, so less light reaches the retina and more of it scatters. A commonly cited figure in Illuminating Engineering Society guidance is that a typical 60-year-old's retina receives roughly a third of the light a 20-year-old's does.
• Macular degeneration takes central vision, which is what reads, sees faces and judges a step edge straight ahead. Strong, well-placed task light helps; glare hurts more.
• Cataracts scatter light, so a bright source in the field of view washes out everything around it.
• Glaucoma narrows the field and slows adaptation to the dark, which makes the walk from a lit room into a dark hall dangerous.

The design standard written for this is ANSI/IES RP-28, the IES recommended practice on lighting for older adults and people with low vision, in its current edition. It is a design recommendation, not a code; pull its tables when a task needs a specific target.

The procedure, worked on one house

The customer is an 81-year-old woman who lives alone. Her retina specialist's note to the family says macular degeneration with early cataracts. Her daughter called because she has started eating cold meals rather than reading the stove, and has twice missed the bottom step on the basement stair to the laundry. Each step below is followed by what it found in her house.

1. Walk the house with her after dark, or with every shade drawn. A daytime survey is lit by windows and tells you nothing about 6 p.m. in November or 2 a.m. Ask her to show you what she cannot see, and watch where she slows down, reaches for a wall or squints. If you skip this, you light the rooms you can see are dim and miss the route she actually struggles on.

Found: she stands at the counter in her own shadow; the overhead fixture is behind her. She does not turn on the hall light at night because the bare-lamp ceiling fixture "hurts." She feels for the basement stair rail in the dark because the only switch is at the bottom.

2. Measure what is there now, at the surface where the task happens. A light meter reads illuminance in foot-candles (fc), the light falling on a surface. Read it on the counter, not at eye level; on each stair tread; on the floor along the night route. Record each reading and where it was taken. Without a before figure you cannot tell her, or yourself, whether the work helped.

Found: counter front 18 fc, counter back under the cabinets 9 fc; hall floor at night, lit only from the bedroom lamp, under 1 fc; basement treads from top to bottom, 2 fc rising to 14 fc at the bottom bulb.

3. Remove the glare before adding light. Glare comes three ways: direct (a bare lamp or bright lens in view), reflected (a glossy counter or polished floor mirroring a fixture back at her), and contrast (a bright window or room seen from a dark one). Adding output to a glaring fixture adds glare. Shield or replace bare-lamp fixtures with diffused ones, aim task light at the surface rather than toward the eyes, and use matte finishes where new surfaces are being chosen. Skip this and the brighter fixture becomes the one she switches off.

Found: the hall fixture is a bare-lamp ceiling fitting, the direct-glare case; the laminate counter is glossy and will reflect any strip mounted at the back of the cabinet.

4. Layer the light: ambient, task and path. Ambient light is the even fill that lets a person move around a room; task light is concentrated on the surface where work happens; path light is the low-level route at night. One ceiling fixture trying to do all three does none of them well. As a shop starting point for a low-vision user, aim for about 50 fc on a working counter, measured at the counter front, and tune with the person; RP-28 gives task-by-task targets when you need them.

Done: a diffused ceiling fixture for ambient, and linear under-cabinet lights with frosted lenses mounted at the front edge of the cabinets, aimed back toward the wall. Front mounting lights the counter from above her hands instead of behind them and keeps the strip out of her line of sight. On the glossy laminate it also throws the reflection toward the backsplash rather than at her eyes, which she confirmed by standing at the counter and saying where it was bright.

5. Light every stair tread, from the side or low, not from straight ahead. A downlight at the top of a stair shines directly into the eyes of someone climbing it, and a single bulb at the bottom leaves the top treads in shadow, which is where a missed step starts. Wall-mounted step lights or a fixture lighting the stair from the side make each tread edge cast a short shadow, which is what tells the eye where the edge is. Pair it with contrast on the nosings. See related: Contrast and Cues for Low Vision.

6. Put switches where a hand finds them in the dark, at both ends of every route. Use rocker switches with a lighted locator at the latch side of each doorway, at a consistent height through the house. Stairs need control at both ends: the IRC (R303.7.1 in the 2021 edition, as adopted) requires a wall switch at each floor level for interior stair lighting where the stair has six or more risers, and the NEC carries a similar rule at 210.70, as adopted. Skip it and she climbs a stair in the dark rather than walk back down to turn a light on.

Done for steps 5 and 6: the basement stair has seven risers, so the new lighting got switches at the top and bottom, plus three step lights on the open side. Treads now read 9 fc at the top and 12 fc at the bottom, with no tread in shadow.

7. Build the night path from bed to toilet. The middle-of-the-night trip is the one where falls happen, and the overhead light is the wrong tool: it blinds an eye that has been dark for hours, and then the hall goes black when she turns it off. Use low-level lights, motion-activated or switched from the bedside, mounted low enough to light the floor rather than the eyes, along the whole route to the toilet, plus a low setting in the bathroom. Warm color (around 2700 K or below) is less disruptive at night; research has linked blue-rich evening light with disrupted sleep, though how much varies.

Done: three motion-activated low-level lights along a 22 ft route from the bed to the toilet, mounted about 16 in above the floor, reading 1 to 2 fc at the floor; a bathroom fixture with a dim night mode.

8. Choose color temperature and color rendering on purpose. Around 2700 K to 3000 K suits living spaces and evening; around 3500 K to 4000 K can help at a task surface where contrast matters. Pick lamps with a high color rendering index (CRI 90 or above), which helps her tell pills, food and wiring colors apart. Keep color temperature consistent within a room, because mixed lamps make surfaces look patchy to an eye that already struggles with contrast.

9. Keep the step between rooms small. An eye that adapts slowly needs neighboring spaces lit to similar levels. Dimmers on the brightest rooms in the evening, and path lighting in the hall, keep her from walking out of a 50 fc kitchen into a hall under 1 fc.

The hazards in the work, step by step

• Rewiring fixtures and switches means working on branch circuits. Open the breaker, lock it, and prove dead on a known live source before and after, per NFPA 70E Article 120 (120.5 in the 2021 edition, renumbered in 2024), with work practices at 29 CFR 1910.333(b)(2). In many states adding switches and circuits is licensed electrical work; if nobody on the crew holds the license, the electrician does it.
• Cutting box holes in plaster in a house built before 1978 can release lead paint dust. Mist the surface, catch debris on plastic, clean with a HEPA vacuum, never dry-sweep. Work in pre-1978 housing that disturbs more than about 6 sq ft of painted surface in a room (the minor-repair threshold for interiors) falls under the EPA's renovation rule at 40 CFR 745 and needs a certified renovator.
• Fishing wire through an attic means heat, poor footing and insulation. Loose, pebble-like gray-brown insulation may be vermiculite, which can contain asbestos: do not disturb it, route around it, and have it tested.
• Working over the stair means a ladder on treads. Never stand a stepladder on stair treads; use a ladder made to adjust for stairs or a work platform, and keep her off the stair while you are on it.
• Restoring power at the end: stand to the side of the panel, not in front of it, as each breaker closes, then test every new fixture, switch and motion sensor before you leave, with the GFCI and AFCI devices on those circuits tested at their test buttons.

What changes the answer

Glaucoma rather than macular degeneration shifts the weight from task light to path light and even transitions, since the hazard is the dark-adapted walk, not the close task. A person who uses a magnifier may want a task light on an arm she can move, not a fixed strip. A renter may need a landlord's agreement for hardwired changes; plug-in and battery fixtures do much of steps 3, 4 and 7 without it. See related: Reasonable Modifications for Tenants. A progressive condition argues for dimmable fixtures with headroom, so the light can rise as her vision falls without a second job. See related: Designing for a Progressive Condition.

How to verify

Re-read every point from step 2 with the same meter at the same places, and record them beside the before figures. Here the counter front went from 18 fc to 62 fc, and the back from 9 fc to 55 fc. The bottom-of-stair reading actually fell, from 14 fc to 12 fc, while the top tread rose from 2 fc to 9 fc; that is the goal, since an even stair beats a bright bottom step.

Then go back after dark with her. She reads the stove dial. She walks the night route with the overhead lights off and the path lights on, and climbs the basement stair using the top switch. If she reaches for a wall or slows where she slowed before, the job is not done, whatever the meter says.

References

• ANSI/IES RP-28, Lighting and the Visual Environment for Older Adults and the Visually Impaired, current edition
• International Residential Code, 2021 edition, R303.7.1, and National Electrical Code 210.70, as adopted by your jurisdiction
• NFPA 70E Article 120 (120.5 in the 2021 edition, renumbered in 2024); 29 CFR 1910.333(b)(2); 40 CFR 745 (lead renovation)
• See related: Contrast and Cues for Low Vision; How to Relocate Controls to a Reachable Height