With smartphones becoming increasingly powerful in recent years, at least 80% of people now rely on them daily. Many new phone owners apply screen protectors to safeguard their displays.But some claim screen protectors harm your eyes. Is there any truth to this? Should you use one at all?
Screen protectors can indeed harm your eyes
Screen protectors inevitably reduce screen transparency. Whether it's a tempered glass protector claiming 98% transparency or a high-definition film boasting 93%, poor-quality protectors can develop scratches over time, further diminishing light transmission.

Reduced screen clarity increases eye strain. Over time, this strains the eyes more and can harm vision.
What kind of screen protectors affect vision? Those with low light transmission.
When choosing a screen protector, light transmission should be the primary consideration. Even the best protectors cannot achieve 100% light transmission.Optical glass currently offers the highest light transmission rate, yet it only reaches around 97%. PET-based screen protectors typically achieve 90% light transmission, while some high-definition options can reach 95%. Since no screen protector achieves 100% light transmission, they inevitably reduce the display quality of the phone screen, thereby affecting vision.
Screen protectors invariably affect light transmission to some degree. Those with higher light transmission cause less eye strain, while those with poorer transmission can harm vision. The market offers a wide variety of options—diamond films, metallic films, privacy films, frosted films, etc.—but materials primarily fall into four categories: PP, PVC, PET, ARM, and glass.
So, should you use a screen protector?
While screen protectors can indeed cause eye strain, their impact is far less severe than the damage caused by prolonged phone use itself. Therefore, if you can consistently reduce your daily phone usage by just one hour, this alone can sufficiently offset any harm from the screen protector.
How to minimize eye strain from screen protectors?
1. Avoid films claiming over 97% light transmittance
Many packaging labels boast "99% light transmittance," but tests prove this figure misleads consumers. The highest transmittance optical glass achieves around 97%. Phone screen protectors cannot match optical glass transmittance, let alone reach "99%."When you see packaging claiming over 97% light transmittance, avoid purchasing it—this figure is false.
2. Replace your screen protector regularly
One way phone screen protectors harm your eyes is through accumulated scratches over time. These scratches reduce light transmission, leading to visual fatigue. To minimize eye strain, replace your screen protector frequently. This prevents excessive scratches from causing eye fatigue and worsening nearsightedness.
3. Reapply if bubbles form
Bubbles on screen protectors obscure text and images, causing eye strain that outweighs any perceived benefit. Reapply immediately if bubbles appear to prevent visual fatigue.
4.Avoid purchasing glow-in-the-dark screen protectors
Popular glow-in-the-dark screen protectors on the market can also cause significant skin damage. Many such protectors are simply standard films coated with fluorescent powder. While they typically contain no radioactive substances, the added fluorescent powder poses risks. Since these protectors are often positioned close to the respiratory tract during use, they can be inhaled. Prolonged exposure may harm the skin and overall health.