It is now certain that accommodation does not affect intraocular tension, so increased accommodative efforts due to wearing the correcting glass for near cannot tend to increase the myopia. This is rather due to the pressure of the extrinsic muscles, whose deleterious action is favored when objects are held close to the eyes.
Reference: Heine L. On the full correction of myopia. Arch Ophthalmol. 1902;31:41.