HEAD-MOUNTABLE DEVICES WITH MODULAR ASSEMBLIES FOR FIT ADJUSTMENT

A head-mountable device can include modules that provide fit adjustment capabilities when assembled together. By providing head-mountable devices with modular features, certain modules can provide fit adjustment capabilities without requiring other modules to be custom designed or available in a wide variety of sizes and/or shapes. For example, a light seal module that provides engagement of a user's face and transmits light from a display element can be coupled to an HMD module. The coupling module that couples the light seal to the HMD module can be provided in a wide variety of sizes and/or shapes to allow a user to select an appropriate one for optimal alignment of an HMD module. Additionally or alternatively, a light seal module can be provided with manual and/or automated adjustment capabilities to achieve the desired fit.