The short answer

Some displays control low brightness by rapidly switching light output. At lower modulation frequencies, sensitive users may experience glare, dryness, headache or dizziness. Refresh-rate changes, unstable automatic brightness, eye-care filters and a high-contrast room can feel similar. A web page cannot measure PWM frequency accurately, but it can help rule out dead pixels, backlight bleed and other visible defects.

A practical first adjustmentRaise brightness to a comfortable range, briefly disable automatic brightness for comparison and avoid a bright screen in a completely dark room. Discomfort limited to very low brightness, with normal use at medium or high brightness, is more consistent with dimming sensitivity than a broken panel.

Compare controlled conditions

Keep the room and content fixed, then read the same text at roughly 20%, 40% and 70% brightness. Note whether comfort changes clearly with brightness. Disable automatic brightness, night mode, third-party filters and automatic refresh switching, then compare again. If discomfort occurs only at low brightness in a dark room, dimming and room contrast are more likely than a full-screen hardware fault.

A phone camera may show moving bands because its rolling shutter interacts with display modulation. This does not mean your eyes perceive flicker at the same intensity. Your sustained reading experience at normal settings matters more. This page is not a medical test; persistent or severe symptoms should be discussed with a qualified healthcare professional.

Step-by-step check

  1. Disable automatic brightness and choose a comfortable level where text is clear rather than forcing the screen to minimum brightness.
  2. Read familiar content—messages, documents or web pages—for about 10 minutes and note dryness, pain, headache or dizziness.
  3. Try a higher refresh-rate setting if available and compare with eye-care filters disabled. Cross-check in another browser or a system application.
  4. Use the solid-color test to rule out fixed flashing pixels. If the screen is uniform but still feels uncomfortable, read the PWM and eye-comfort buying guide.

When to contact support

If obvious full-screen flicker, brightness jumps, tearing or other display abnormalities remain at medium and high brightness, save video evidence and request service to rule out driver or hardware problems. Sensitivity limited to low-brightness dimming on an otherwise functional panel is usually not classified as a defective screen; settings, room lighting or a different product may be more effective solutions.

When shopping, compare high-brightness DC-like dimming, high-frequency PWM, anti-reflective treatment and your own viewing comfort rather than relying only on an “eye care” certification. Also review screen color cast and the office monitor buying guide.