If you have ever been to the acupuncturist, you might have received "e-stim" or electrical stimulation on the acupuncture needles. Or you might have heard of TENS units at your chiropractor or physical therapist.
In this article, we will introduce different types of micro-current therapies and discuss the current state of research for their use in the acupuncture clinic, especially for the treatment of eye disorders.
Types of ocular micro-current therapies:
Classic electro-acupuncture (transcutaneous): micro-current is hooked up to the needles
Orbital electrical stimulation: patches are applied over the closed eyes
Trans-corneal electrical stimulation: a special probe delivers current directly into the eye
Proven effects of Micro-current for the eyes
Although the exact mechanism of action of micro-current has not yet been established scientifically, research suggests that electrical stimulation device approximates the level of electrical activity present in a healthy eye, resulting in stimulating retinal activity and energizing dormant cells, as well as improving microvascular circulation, nerve conduction and velocity.
1. Micro-current improves blood circulation in the eyes [1-4]
Micro current improves blood flow, therefore boosting the cells' ability to rid themselves of waste products. Cells need to take in nutrients and eliminate waste like all other living organisms.
2. Micro-current increases cellular activity 
Your cells' energy source is called ATP. The eyes consume a huge amount of ATP.
Micro-current has been shown to increase ATP production in the retina, therefore benefiting vision, in particular for people whose vision has already started to decline.
It activates the dormant cells who have not been damaged yet to restore some vision.
Micro-current for Macular Degeneration & Retinitis Pigmentosa
An FDA-guided and -supervised study revealed that micro-current stimulation resulted in significant vision improvements in 61% of patients suffering from dry macular degeneration. The research showed promise that micro-current stimulation could also help patients with diabetic retinopathy or retinitis pigmentosa.
Here are two more studies :
Transcorneal Electrical Stimulation for Patients With Retinitis Pigmentosa: A Prospective, Randomized, Sham-Controlled Follow-up Study Over 1 Year
2 year study, 114 patients, Grace Halloran, PhD
18 patients with AMD - 16 improved. 78 had Retinitis Pigmentosa - 62 improved
18 patients had various retinopathies, 16 improved.
14 remained unchanged (stable), 2 continued to lose vision, although only slightly.
Published 1997, Bioelectrical Stimulation in an Integrated Treatment for Macular Degeneration, Retinitis Pigmentosa, Glaucoma, CMV, and DR; Fourth Annual Symposium on Biologically Closed Electrical Circuits, Mankato University, MN, October, 1997
How we use micro-current in the acupuncture clinic
1. Electrical stimulation of acupuncture needles
Research shows that micro-current added to acupuncture points around the eyes reduces intra-ocular pressure in patients suffering from glaucoma. (link)
We also use electro-stimulation on needles that are placed in the body away from the eyes.
2. Micro-current with microstile: seeing flashing lights
Our brain thinks the micro-current stimulation is some sort of light and reports it as such. If the current is pulsing at nine times per second (9 Hz), then your brain thinks you are seeing a light flashing at nine times a second. But there is no light.
Patients with retinal degeneration may not see flashing. This is normal and common.
With the stimulation of the micro-current, the dormant cells begin to be activated, and when people finally start to see the flashing, they know their eyes are starting to heal.
3. At home
You will be taught by your acupuncturist how to use the device at home. Most practitioners recommend 20 minutes of treatment twice a day. Taking two days off each week is important, and taking a rest from treatment of 1 to 2 weeks every two months is recommended.
 Kjartansson J, Lundberg T 1990 Effects Of Electrical Nerve Stimulation (ENS) In Ischemic Tissue. Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery 24: 129-134
 Debreceni L, Gyulai M, Debreceni A, Szabo K 1995 Results Of Transcutaneous Electrical Stimulation (TES) In Cure Of Lower Extremity Arterial Disease. Angiology 46: 613-618.
 Kaada B 1982 Vasodilation Induced By Transcutaneous Nerve Stimulation In Peripheral Ischemia (Raynauds Phenomenon And Diabetic Polyneuropathy). European Heart Journal 3:303-314
 Kaada B 1983 Promoted Healing Of Chronic Ulceration By Transcutaneous Nerve Stimulation. (TNS) VASA 12: 262-269
 Cheng, Ngok, The Effects Of Electrical Current On ATP Generation, Protein Synthesis And Membrane Transport In Rat Skin, Clinical Orthopedics and Related Research, 171 (Nov.-Dec. 1982) 264-271