Patently Apple recognized Apple's patents for Head Mounted Devices and smartglasses as a coming trend many years ago and it's why we broke this out as a major category and archive. Beginning this year, there was a new push in patents covering the introduction of addressing the use of prescription lenses for future headsets and glasses.

In January we posted a report titled "Apple Invention Details a Prescription Lens System for a Future Head-Mounted Display Device," and in early June we posted a report titled "Apple Invents a Vision Correction System for Headsets that eliminates the need for a user to wear prescription glasses to enjoy MR Content."

Then in late June we posted yet another patent on this subject titled "Apple Patent illustrates Future Smartglasses Offering a Modular Design allowing users to exchange parts for Different Functionality." It was in this patent filing that we learned for the first time that Apple could provide clip-on or snap-in prescription lenses for smartglasses as noted in the patent figures below.

Apple noted in this patent that "Additionally or alternatively, one display element can provide optical correction (prescription) and the other display element can provide different or no optical correction. The patent FIGS. below illustrate snap-in or clip-on prescription lenses for smartglasses.

The other methodologies of addressing prescription lenses are designed to work with Head Mounted Display systems and Apple has a few methodologies that they're considering.

Today the US Patent & Trademark Office published a patent application from Apple titled "Display System with Virtual Image Distance Adjustment and Corrective Lenses." It addresses  a new prescription lens system designed for their larger and more sophisticated Head Mounted Device using a unique magnets-based system. 

Apple's invention covers another head-mounted device that may have a display that displays computer-generated content for a user. The head-mounted device may have an optical system that directs the computer-generated content towards eye boxes for viewing by a user.

In one illustrative configuration, the optical system may include a non-removable lens and a removable lens through which an opaque display is viewable. The removable lens may serve as a vision correction lens and may have radially increasing lens power to compensate for field curvature in the optical system.

In another illustrative configuration, the optical system may be a see-through optical system that allows the user to view a real-world object through the optical system while receiving the computer-generated image.

This type of system may have a waveguide with an output coupler interposed between at least first and second lenses. The display may provide an image to the waveguide. The output coupler may couple the image from the waveguide towards the eye box through the first lens.

The first lens may be a projection bias lens that adjusts virtual image distance for the image.

The second lens may be a corresponding compensation bias lens that compensates for the first lens and allows the user to view the real-world object normally.

If desired, the first lens or a removable third lens in the optical system may serve as a vision correction lens.

Later in the patent Apple notes that "When it is desired to customize the optical system in the Head Mounted Device (HMD) for a given user (e.g., a user with astigmatism), a lens #82 that corrects the given user's astigmatism may be temporarily coupled to magnets #26M (and thereby temporarily installed within the HMD. The Magnets #26M are shown in FIG. 3 Below.

When a user with a different prescription (e.g., a nearsighted user with no astigmatism), a different customized lens #82 may be removably installed within the system# 96 (Shown in FIG. 3) to correct for that user's vision defect.

In addition, lens #82 may include both a vision correction component (e.g., a negative lens component to correct for a user's nearsightedness) and a virtual image distance adjustment component (e.g., a negative lens component to place a virtual object at a desired virtual image distance.

Apple's patent FIG. 2 below is a top view of an illustrative head-mounted device; FIG. 3 is a diagram of an illustrative display and associated optical system with removable lens structures.

Lenses in system 96 may include regions of different strength. For example, lens 82 may be a bifocal lens, trifocal lens, progressive lens, or other lens with multiple strengths in different regions.

In order for Apple to reach the maximum number of users for their future HMD, Apple recognizes that no other HMD system on the market today addresses the needs of those with prescription glasses. By enabling the corrective lenses to simply drop into the head set they are ensuring maximum comfort for users who won't be forced to wear their glasses in the headset.

Three of the key patents today were all related to Apple's future HMDs to illustrate how much of a priority this project is to Apple. One of the other patents covered  presented methods of moving objects in a virtual world using eye gaze menus and methods along with touch controls and Siri.

Another report covered how an HMD could provide students and those in the workplace with the ultimate privacy mode where only the user wearing Apple's HMD will be able to see the documents and emails that they're working on.  

Apple's patent application 20200225477 that was published today by the U.S. Patent Office was filed back in Q4 2019. Considering that this is a patent application, the timing of such a product to market is unknown at this time.