Eyes on Drugs: Substance Misuse and Eye Changes

Can Substance Misuse Impact the Eyes?

Misusing certain substances can have serious adverse effects on the eyes—ranging from dilated pupils related to alcohol consumption to vision loss, which may be associated with intravenous drug misuse.¹ Thus, the type and severity of the ocular manifestations brought on by substance use depend on the substance, the method of use, and individual health factors.¹

It’s important to note that some substance-related eye issues occur within minutes of drug or alcohol use—such as red eyes, brought on by marijuana use. Other changes, however, may happen over time and start as another substance-related problem altogether. These can include:¹

• Vitamin deficiencies.
• Increases in general inflammation.
• Weakening of the immune system.
• Changes in blood flow.
• Changes in eye pressure.
• Extreme electrolyte changes.
• Pupil dilation changes.
• Infections.

To be sure, substance-related adverse health effects impact all areas of the body—from major organs, such as the heart, brain, and lungs to specific body parts like the nose, teeth, skin, and, of course, eyes.^1,2

Impact of Different Drugs on Eyes

As previously mentioned, the type and severity of drug- or alcohol-involved eye conditions that develop depend on the substance and on the method of use.^1,3-7

Alcohol may have both short and long-term effects on the eye. While intoxicated, a person may experience double vision, blurry vision, poor night vision, less sensitivity to environmental or distance changes, or uncontrolled eye movements. Chronic, heavy alcohol consumption can lead to a vitamin B1 (thiamine) depletion. This nutritional deficiency can cause Wernicke-Korsakoff syndrome (WKS), a life-threatening brain disorder that is actually comprised of two conditions. The first part of WKS is Wernicke’s encephalopathy, a severe and temporary condition characterized by abnormal eye movements and vision changes, among other symptoms. For individuals who suffer from Wernicke’s encephalopathy, the nerves in the eye may become paralyzed, which can lead to involuntary eye movements, drooping eyelids, and difficulty tracking objects properly.

Benzodiazepines like alcohol can cause altered, double, or blurry vision during intoxication.

Cigarette smoking can lead to cataracts of the crystalline lens–an area of the eye that produces one-third of the image the brain processes by focusing light onto the retina. Additionally, eye redness, irritation, dry eye, inflammation, and an increased risk of eye cancers are all conditions that have been reported by individuals who smoke.

Cocaine use leads to dilated pupils. Case reports suggest that prolonged cocaine use can lead to blood clots that block blood flow from the retina (retinal vascular occlusive disease), which can cause vision loss.

Hallucinogens such as LSD, phencyclidine (PCP), and mescaline may cause visual hallucinations. PCP intoxication may also cause individuals to experience horizontal or vertical involuntary, rapid, repetitive eye movements (nystagmus).

Heroin directly affects the eyes by constricting the pupil and causing pinpoint pupils regardless of the method of use—smoking, snorting, or injecting it. Intravenous use of heroin or other opioids or substances carry additional risks, including talc retinopathy, an ocular condition characterized by the presence of small, yellow, glistening crystals found inside small retinal vessels and within different retinal layers. These crystals can be associated with blood clots that block the main vein where blood flows out of the retina (retinal vascular occlusive disease) and retinal ischemia (which occurs when there is an inadequate blood supply to the retina). Additionally, contaminated needles employed for intravenous substance use can potentially introduce dangerous microorganisms into the bloodstream, which then travel to the eye and cause infections and an inflammation of the inner coats of the eye (endophthalmitis), a potentially blinding condition.

Marijuana can cause redness, pupil dilation, and a slowed ability to focus during intoxication. Uncontrolled, repetitive eye movements is also common with marijuana misuse. With chronic use, an individual may experience ongoing decreased eye muscle function.

Methamphetamine and other stimulants cause dilated pupils. A more serious condition associated with the use of meth, however, is retinal vascular occlusive disease, which occurs when a blood clot impedes the flow of blood from the retina.

Long-Term Impact on the Eyes from Substance Misuse

Some substance-related eyes conditions, such as double vision, pupillary changes, eyelid twitching, and weakened night vision may be temporary—only existing as long as the substance remains in the body. However, other conditions, like retinal ischemia (when the retina does not receive an adequate blood supply), and optic neuropathy (which occurs when the optic nerve, responsible for transferring visual information from the eye to the brain, becomes damaged), may have a more lasting impact on vision and overall eye health.

Additionally, not all eye-related health conditions are immediately apparent. Instead, some ocular issues develop insidiously with chronic substance use. Some of these conditions include:^1,3,8

Age-related macular degeneration (ARMD). This cause of central vision loss or impairment typically occurs in people over age 50 regardless of long-term health. However, some studies suggest that ARMD can be worsened by alcohol and tobacco misuse.

Keratitis. An inflammation of the corneas—that can be worsened by a weakened immune system—keratitis can distort an individual’s vision. There is some evidence that topical anesthetics and cocaine can lead to the development of keratitis, and persistent keratitis can result in infectious ulcers in the corneas and corneal perforation.

Dry eyes. Persistent dry eyes, problems forming tears, and feeling as though eyes are irritated are issues that can develop due to heavy alcohol consumption—although they are not related to current alcohol intoxication.

Endophthalmitis. This condition, an inflammation inside the eyes usually caused by infection, may be associated with the use of dirty needles to inject drugs. The bacteria enters the bloodstream and spreads throughout the body, including to the eyes.

Glaucoma. Changes in blood pressure alter the fluid pressure in the eye itself, and long-term increases in intraocular pressure can lead to glaucoma. Some studies suggest a link between alcohol use disorder and substance-induced glaucoma, while many population-based and case-controlled studies have found no association between the two, so the connection is debatable.

Nystagmus. This repetitive, rapid, involuntary movement of the eyes can be a symptom of intoxication from a variety of substances.

Retinal vascular occlusive disease (RVOD). An eye condition that affects the retina, the light-sensitive layer of tissue in the back of the eye, is caused by changes in blood pressure or a blood clot, which prevents healthy blood flow to and from the eye. Swelling, bleeding, and abnormal blood vessel growth in the retina can eventually cause partial or total vision loss. RVOD is related to several conditions, including high blood pressure, cholesterol, diabetes, glaucoma, inflammatory problems, and blood clotting—all of which can develop as a result of substance misuse and addiction.

Retinal ischemia. Characterized by the death of cells and sections of tissue all over the retina, retinal ischemia can consequently impair vision.

Talc retinopathy. The buildup of white or yellowish crystalline particles in the vascular areas of the eye—which some research suggests may be associated with some intravenous and intranasal drug misuse—talc retinopathy may lead to RVOD and retinal ischemia.

Toxic cataracts. Long-term substance misuse can lead to the development of cataracts due to the poisonous effects the substance can have on the body.

Wernicke’s encephalopathy. This condition is sometimes caused by excessive, long-term alcohol consumption. One of the symptoms associated with the condition is optic neuropathy, or nerve death in the cluster connecting the eye to the brain, which can lead to involuntary eye movements, drooping eyelids, and the inability to track objects.

Yellowed eyes. Substances such as alcohol, opioids, and stimulants, among others, can damage the liver, leading to liver diseases, some of which can cause jaundice (yellowing of the skin and the whites of the eyes). Additionally, hepatitis C, which can be contracted by sharing needles, can also cause liver failure and jaundice.

Getting Help for Drug and Alcohol Misuse or Addiction

The good news is that it’s not too late to get help if you or someone you care about struggle with substance misuse or addiction.

American Addiction Centers (AAC) has drug and alcohol rehab centers in several locations across the United States. Our teams of trained physicians, healthcare professionals, counselors, and more can help you recover from addiction, and sustained recovery can improve your overall health, including your vision.

Call today to speak to one of our compassionate and knowledgeable admissions navigators. These individuals, many of them in recovery, are available 24/7 to listen to your story, answer your questions, explain your options, and help get you on your path to recovery.