PWM Flickering and Health Impact on iPhone Displays (16 Pro Max)

I am writing to share some concerns regarding the use of Pulse Width Modulation (PWM) for brightness control on OLED displays in recent iPhone models, such as the iPhone 16 Pro Max. While I greatly appreciate the advancements in display quality, PWM dimming can negatively impact users who are sensitive to flicker, especially at lower brightness levels. I wanted to highlight some of the issues and suggest possible areas for

improvement.

Health Concerns with PWM Flickering:

1. Eye Strain and Fatigue: For PWM-sensitive users, the rapid flickering, especially at lower brightness levels, can cause significant eye discomfort and fatigue, making it challenging to use the device comfortably over extended periods.

2. Headaches and Migraines: Flickering can trigger headaches and migraines in certain individuals. This issue seems particularly pronounced in OLED iPhones due to the nature of PWM and is especially noticeable when using the device in dim environments.

3. Sleep Disruption: Although features like Night Shift are available, the on-off cycling of light that occurs with PWM still has the potential to disrupt natural sleep cycles in some individuals when using the device at night.

Suggested Solutions:

• Alternative Dimming Options: Implementing a feature like DC dimming, which adjusts brightness without rapid flickering, could be helpful for PWM-sensitive users.
• PWM Sensitivity Mode: An optional "Low PWM" mode or similar feature could allow users to control how brightness is adjusted, making the device more accessible to those affected by PWM flicker.
• User Awareness and Education: Providing information in Settings about PWM and its effects would help users make more informed choices about brightness settings and health impacts.

Apple has a strong reputation for creating user-centred products, and addressing the PWM issue would significantly enhance accessibility for many customers. I hope Apple will consider these concerns in their development process as a solution that could make a significant difference for PWM-sensitive users.

I look forward to this issue being resolved.