The sapphire displays on pricier Apple Watches are tougher to read than cheaper models with glass displays, says researcher
It all boils down to the physical properties of sapphire, which is incredibly difficult to scratch but reflects nearly doubles the amount of reflected ambient light when compared to glass.
The Apple Watch is the first device from Apple to get a sapphire display, with both the Apple Watch and Apple Watch Edition tiers using sapphire, but the entry-level Apple Watch Sport model features a display made of strengthened "Ion-X" glass.
"The much higher Reflectance of sapphire compared to glass almost doubles the reflected ambient light, which is fine for traditional watches that work by reflecting ambient light, but significantly washes out the image contrast and color on emissive smart watch displays," display expert Raymond Soneira of DisplayMate writes in the report. "It's an interesting compromise between the luxury and scratch resistance of sapphire versus optical performance."
Soneira also points out that sapphire displays have a worse viewing angle when compared to glass displays, but says an upcoming form of sapphire that's specially treated to compensate for the high reflectance could offer a solution.
"In order to increase the use of sapphire for displays, the sapphire industry will need to modify the optical properties of sapphire without significantly affecting its scratch resistance and other mechanical properties," Soneira writes. "It can't be done using traditional Anti-Reflection optical coatings which scratch easily. A specially treated Enhanced Sapphire will soon be available that delivers both high scratch resistance and low Reflectance."
So if you're looking for the most durable and protective Apple Watch, you'll always be better off springing for the more expensive Apple Watch and Apple Watch Edition models. But if you're looking for another excuse to save some money and go with the entry-level Apple Watch Sport, you can now brag that your watch is easier to read.
You can read Soneira's full report for DisplayMate by clicking here.