Nikki Neisler
Co-founder, Sundown
Nikki Neisler is a co-founder of Sundown. The Sundown blog covers Mac display settings, screen warmth and screen use after dark.
Articles by Nikki
Computer Vision Syndrome on a Mac: What the Research Says
Computer vision syndrome is mostly about blinking, focus and dry eye, not your screen's color. What the research says about causes, remedies and your Mac.
Delayed Sleep Phase and Your Mac Screen at Night
Delayed sleep phase needs a clinician. What the one glasses trial in DSPD patients found, and an untested warmth example for a night owl's Mac screen.
Screen Time Before Bed: A Mac Evening Routine by Kelvin
Screen time before bed, done better: what the eReader and room-light studies found, and a two-hour Mac routine with the warmth to set at each step.
Shift Work Sleep and Your Mac Screen: A Kelvin Guide
Shift work sleep disorder needs a clinician. Your Mac screen needs a plan: the warmth to set before your sleep window on nights, lates and rotating shifts.
PWM Monitor Flicker: Why Your Screen Hurts (And How to Fix It)
Monitors dim by strobing the backlight thousands of times a second. Most people never see it and some get headaches. How to test for PWM and stop it.
Best Circadian Health Apps in 2026: 9 Tools That Actually Work
Nine circadian apps for 2026 across display filters, sleep trackers, light therapy and chronobiology, each checked against the research behind it.
Best Screen Dimmer Apps for Mac in 2026: 6 Tools Compared
Need your Mac dimmer than the minimum brightness allows? Six Mac dimmer apps compared on eye comfort and how far each one actually goes down.
How to Reduce Eye Strain on Mac: 7 Settings to Change (2026)
Dimming a Mac screen can increase invisible flicker, and Night Shift stops at a warm white. Seven settings that change how your screen is lit and colored.
Best Mac Display Health App 2026: Complete Guide
Mac display health comes down to four things: blue light, PWM flicker, temporal dithering and scheduling. Every app compared against all four of them.
Blue Light and Sleep: What Your Mac Display Does to You
Evening screen light suppresses melatonin and pushes your body clock later. What the research shows, and how far a Mac display can be shifted.
Red Screen Filter for Mac: Deep Red
Night Shift stops at warm white and f.lux's regular warmth settings at deep orange. Here is what deep red looks like on a Mac and how to set it up.
Display Dithering on Mac: The Hidden Flicker Source Your Blue Light App Won't Fix
Every Apple Silicon Mac flickers at the pixel level through temporal dithering. It is not PWM, most people never see it, and some Mac apps can turn it off.
Flicker-Free Mode for Mac: How Sundown Dims Through Gamma Instead of the Backlight
Some MacBooks dim by strobing the backlight on and off. Flicker-free mode holds the backlight at full power and dims through the gamma table instead.
Fix Screen Flicker Headaches on MacBook (2026 Guide)
MacBook flicker comes from two invisible sources: PWM backlight dimming and Apple Silicon temporal dithering. How to tell which, and fix it.