To explore the theoretical basis for treatment of myopia with intraorbital perpendicular acupuncture from the perspective of "imbalanced essence and tendons". It is believed in "imbalanced essence and tendons" that the imbalance of "essence and tendons" in the eye is associated with the occurrence and development of myopia. The ocular blood supply system and the choroid and retina enriched in blood vessels

are collectively referred to as the "essence and blood" of the eye. The tissues and structures responsible for visual function

including the cornea

lens

sclera

intraocular muscles

suspensory ligaments and extraocular muscles

are collectively as the "tendons/sinews of meridians" of the eye. Based on "imbalanced essence and tendons"

the theoretical evidences of intraorbital perpendicular acupuncture in treatment of myopia can be summarized as follows: concerning "regulating essence and blood"

acupuncture directly stimulates the meridians around the eye to relieve spasm

regulate essence circulation in the eye

improve the blood supply and oxygen supply of local tissues

and enhance the nourishment of the eyeball and its appendages. Regarding "regulating tendons"

acupuncture acts on nourishing the tendons/sinews of meridians in the eye and promotes the recovery of self-regulation of local tissues. In summary

the intraorbital perpendicular acupuncture collaboratively ameliorates the biomechanical environment and nutritional metabolic state of the eyeball and restores ocular homeostasis through "essence-tendon intermodulation".