Eyes not adjusting to dark

Warning signs of a serious eye problem

Eyes aren’t exempt from the wear and tear of aging. Some of the age-related changes in the eyes are annoying but not serious — for example, it can become difficult to focus on near objects, and eyelashes may thin out a bit. But other changes can be serious eye problems that threaten vision.
With age, the eyes’ ability to stay lubricated starts to wane. This can leave eyes feeling irritated, sticky, dry, or gritty. The lens of the eye can become less elastic. Night vision may also start to suffer, which can pose problems when driving at night. In contrast, cataracts, macular degeneration, and diabetic retinopathy can rob you of your sight.
How do you know if an eye problem is a nuisance or the start of something serious? The following signs and symptoms warrant a call to your doctor. Catching serious eye problems early can help preserve your vision. Even non-vision-threatening eye problems can be treated to keep your eyes comfortable and your eyesight as sharp as possible.

Call your doctor if you experience any of the following:

  • Change in iris color
  • Crossed eyes
  • Dark spot in the center of your field of vision
  • Difficulty focusing on near or distant objects
  • Double vision
  • Dry eyes with itching or burning
  • Episodes of cloudy vision
  • Excess discharge or tearing
  • Eye pain
  • Floaters or flashers
  • Growing bump on the eyelid
  • Halos (colored circles around lights) or glare
  • Hazy or blurred vision
  • Inability to close an eyelid
  • Loss of peripheral vision
  • Redness around the eye
  • Spots in your field of vision
  • Sudden loss of vision
  • Trouble adjusting to dark rooms
  • Unusual sensitivity to light or glare
  • Veil obstructing vision
  • Wavy or crooked appearance to straight lines

For more information about preventing and treating eye disease, read The Aging Eye, a Special Health Report from Harvard Medical School.

Image: Bigstock

Disclaimer:
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

Normal Vision Changes

Learn more about ways to protect your eye health, including:

  • The different types of eye care professionals
  • The components of a comprehensive eye examination
  • Questions to ask your eye doctor
  • Check out our Getting Started Kit for more ideas to help you live well with low vision.
  • Sign up with VisionAware to receive free weekly email alerts for more helpful information and tips for everyday living with vision loss.

Vision Changes in the Older Eye

The most common age-related vision changes and their effects on everyday activities can include the following:

  • Increased sensitivity to glare

    Being able to see clearly when exposed to reflected light or bright sunlight—especially outdoors on a sunny day or in a hallway with highly polished floors—requires absorptive sunglasses or other adaptations to control glare and to see the environment clearly.

  • Increased lighting requirements

    Most older adults require three to four times more light than they did previously to perform many everyday activities. Seeing clearly enough to read, write, sew and knit, or perform home repairs usually requires a brighter, more focused light in addition to reading glasses or bifocals.

  • More time required to adjust to bright light and/or darkness

    Adjusting to changes in light levels between bright and dark areas—such as leaving a dim building lobby and walking outside into bright sunlight or moving out of a restaurant with dim lighting into daylight—can take two to three times longer than it used to.

  • Reduced contrast sensitivity

    In the photo at left, it is difficult to see the white lamp and white bedding against the white wall and white table. Seeing an object clearly against a background of the same color becomes more difficult and requires stronger contrast to make it stand out.

  • Decreased ability to judge depth perception

    Difficulties judging distances accurately—the height of a step or curb, or the depth of a bathtub, for example—requires close attention to safety cues such as color, contrast and lighting. Shadows and shadow patterns may be incorrectly interpreted as drop-offs or obstacles.

  • Decreased ability to focus close up

    As the eye muscles that control the switching of focus from far to near begin to lose flexibility, it becomes more difficult to focus on things close up. Seeing clearly enough to read a newspaper, sign your name, or sew usually requires reading glasses to accommodate this change in focus.

  • Decreased color sensitivity

    Telling certain colors apart becomes more difficult when matching clothing or playing card games. In particular, it is often difficult to distinguish navy blue from brown or black; blue from green or purple; and pink from yellow or pale green.

Why do I see better on some days than on others?

All of us experience good days and bad days, in terms of our general health. However, if you experience any of the following vision changes, it’s recommended that you contact your eye doctor immediately:

  • Needing frequent changes in your eyeglass prescription
  • Severe, sudden eye pain
  • Recurrent pain in or around the eye
  • Sudden hazy, blurred, or double vision
  • Seeing flashes of light or sudden bright floating spots
  • Seeing rainbows or halos around lights
  • Seeing floating “spider webs”
  • Seeing a “curtain coming down” over one eye
  • Sensing a “cup filling up with ink” in one eye
  • Unusual, even painful, sensitivity to light or glare
  • Swollen, red eyes
  • Changes in the color of the iris
  • White areas in the pupil of the eye
  • Sudden development of persistent floaters
  • Itching, burning, or a heavy discharge in the eyes
  • A sudden change in vision
  • See Symptoms of Vision Problems for additional indicators of vision problems that may include difficulties with daily living activities.

At any age, it’s important to have your eyes checked regularly. If symptoms or concerns arise, contact your eye care professional as soon as possible.

By: Richard Gans, MD

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

The lack of daylight in the evening can limit some people’s ability to see and get around. But it doesn’t have to be that way.

Night blindness (nyctalopia), the inability to see well at night or in poor light, is not a disease. It’s a symptom of an underlying condition. In most cases, it’s treatable; in others, it’s not. Fortunately, severe forms of night blindness are very rare.

5 causes for night blindness

There are multiple reasons why you might have trouble seeing in the dark:

  1. Nearsightedness can make it difficult to see well in the distance in the dark, particularly if you don’t have strong enough glasses or contact lenses. In that case, a new prescription might be all that’s necessary to correct your problem.
  2. Certain medications can also cause temporary problems with night vision. Some medications can alter the size of your pupils, which might make it difficult to see in low-lit conditions. There are also medications that slow down the eye’s ability to adapt from bright conditions to dimly lit conditions. This causes a temporary inability to see in the dark until the eye is able to adapt. Talk to your doctor if you are concerned about how your medications are affecting your vision.
  3. Cataracts, which cloud the natural eye lens, are another treatable cause of night vision problems. As a cataract forms, less light can enter the eye, which means you’ll need more light to see. People with cataracts frequently complain of difficulties driving at night. Surgery to remove the cataract can resolve this problem.
  4. Nutritional deficiencies can also decrease your ability to see in the dark. Replenishing the deficiency can often help to restore your night vision.
  5. Retinitis pigmentosa is one of several hereditary diseases that cause a permanent deficit in night vision. Since this condition is genetic, it can affect children as well as adults. Retinitis pigmentosa results in deterioration of the retina, which is the part of the eye that senses light. If you have this disease, you may have difficulty getting around because it also affects peripheral vision and can even cause problems in normal lighting conditions. There are lifestyle adjustments you can make, but unfortunately no curative treatment currently exists.

Adjusting to permanent night blindness

Most common causes for night blindness are treatable. However, there’s no effective treatment to stop or cure some, like retinitis pigmentosa. So, in those rare types, you’re going to have to adjust your lifestyle to accommodate your condition. You won’t be able to drive at night, so you’ll need to find alternative transportation if you’re planning to go out after dark.

You may also want to carry an extra light source with you, like a flashlight, so you can provide your own light when you’re not in an ambient setting. And if you have this condition, it’s very important that you keep any appointments with your eye doctor.

When to call a doctor

Many eye diseases have no symptoms, which is why I tell my patients it’s important to get a routine eye exam every year whether you think you have a vision problem or not. Regardless, if you begin to experience a progressive loss of nighttime vision, your condition is most likely correctable, so make an appointment for an eye exam.

Migraines are one of those health conditions experts are still working to fully understand. The thinking is that activity in certain nerve cells makes blood vessels in your brain dilate and also causes a release of inflammatory substances like prostaglandins, which can create pain.

The mechanism behind the light sensitivity specifically may be related to irritation of the trigeminal nerve, a cranial nerve that’s responsible for sensation in your face, Ilan Danan, M.D., M.Sc., a sports neurologist at the Center for Sports Neurology and Pain Medicine at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles, tells SELF. All light can be tough to deal with when you have a migraine, but you might find that specific types, like fluorescent light, are particularly hard to take, Dr. Danan says.

It’s not just that having a migraine can induce sensitivity to light—it can kind of work the other way around, too. Bright lights are a well-known migraine trigger, along with a multitude of other things like fluctuations in estrogen levels, foods like aged cheeses, alcohol and caffeine, stress, and changes in your sleep pattern, according to the Mayo Clinic.

If you struggle with migraines, talk to your doctor about treatment options. The right migraine treatment is so individual for each person, but yours could include pain medications to get through migraines as they happen along with preventive ones to avoid them in the first place.

4. A concussion

A concussion is a traumatic brain injury that impacts the way your brain functions and is usually caused by a blow to the head, according to the Mayo Clinic. The effects are typically temporary, but they can be subtle and may not show up immediately. Then, they can last for days, weeks, or even longer.

Some symptoms might show up soon after the head injury, including a headache, temporary loss of consciousness, confusion, amnesia about what caused the concussion, dizziness, nausea, vomiting, slurred speech, appearing dazed, and being tired, but some people may have delayed symptoms, like having trouble concentrating or remembering things, trouble sleeping, personality changes, depression, issues smelling or tasting things, and, yup, sensitivity to light, the Mayo Clinic says. It’s pretty rare for someone with a concussion to just have sensitivity to light without the headache—the two usually go together, Dr. Danan says.

Experts typically recommend resting—both physically and mentally—after you get a concussion, since it will help your brain heal more quickly. Beyond that, if you have a concussion, your doctor can recommend treatment for your specific symptoms, like pain relievers if your headaches refuse to GTFO.

5. Keratitis

Keratitis is corneal inflammation that can come with a whole host of signs that your eyes are crying out for help, according to the Mayo Clinic. There are various forms, like bacterial keratitis, viral keratitis, fungal keratitis, keratitis from a parasite called Acanthamoeba, and non-infectious keratitis. Most of those are self-explanatory save for that last one; non-infectious keratitis describes corneal inflammation that happens due to something like wearing your contacts for too long or making other common contact lens mistakes.

No matter the cause, corneal inflammation can distort light that enters your eye, causing sensitivity, Christopher J. Rapuano, M.D., chief of the cornea service at Wills Eye Hospital in Philadelphia, tells SELF. Other symptoms of keratitis include eye pain, redness, blurred vision, excessive tearing, feeling like something is in your eye, and eye discharge, the Mayo Clinic says.

Proper keratitis treatment really depends on the cause. Using an antibiotic won’t help a case of viral keratitis, for example. That’s why it’s so important to see your eye doctor if you think you’re dealing with keratitis. They can prescribe antibiotics if your case is bacterial or due to Acanthamoeba, antifungals if a fungus is to blame, or antivirals if those are necessary. They can also recommend lifestyle treatments that can help with discomfort, like not wearing contacts until your keratitis clears up.

6. A corneal abrasion

In a (yikes-worthy) nutshell, a corneal abrasion means that you have a cut or scratch on your eye. While a scratch basically anywhere else on your body might be NBD, a scratch on your eye is a different story. “It can be very painful,” Nirali Bhatt, M.D., assistant professor of clinical ophthalmology at Penn Medicine, tells SELF.

Rafael Caruso, an investigator in the National Eye Institute’s Ophthalmic Genetics & Visual Function Branch in Bethesda, Md., guides us to an answer.

If we go from the outdoors on a bright sunny day into a very dimly lit room, we are hardly able to see our surroundings at first. As time goes by, however, we gradually become able to detect the room’s contents. This phenomenon is known as “dark adaptation,” and it typically takes between 20 and 30 minutes to reach its maximum, depending on the intensity of light exposure in the previous surroundings.

The human retina can perform its light-detection function in an astounding range of light intensities, from bright sunlight to dim starlight, by relying on two types of light-sensitive cells, or photoreceptors. The first, the cones, evolved for day vision and can respond to changes in brightness even in extremely high levels of illumination. (Cones are unable to respond to light reliably in dim illumination, however.)

Photoreceptors for night vision are called rods. Rods can act as light detectors even in extremely low levels of illumination but are ineffective—they are known to “saturate”—in bright light. Remarkably, rods can respond reliably to a single visible light photon, so they operate at the physical limit of light detection.

Both cones and rods participate in dark adaptation, slowly increasing their sensitivity to light in a dim environment. Cones adapt faster, so the first few minutes of adaptation reflect cone-mediated vision. Rods work slower, but since they can perform at much lower levels of illumination, they take over after the initial cone-mediated adaptation period. This is actually a general feature of many sensory systems: if a sensation relies on stimulation of more than one type of receptor cell, the most sensitive receptor type at any given time is the one that mediates sensation.

So, what happens in the cones and rods during dark adaptation? To attempt to answer this question we need to first consider the mechanism underlying cone and rod function. The only light-mediated event in vision is the interaction of visible light photons with protein molecules in the photoreceptors known as cone or rod opsins, which are also known as “visual pigments.” Human cones have one of three types of opsin, each with a slightly different sensitivity to the spectrum of light, which is relevant for color vision. Rods, on the other hand, have a single form of opsin called rhodopsin. In vertebrates, all photoreceptor opsins contain a molecule called retinal, or retinaldehyde. (The ultimate source of retinal is dietary vitamin A; this is the reason why an early sign of vitamin A deficiency is night blindness.)

The absorption of a photon by a molecule of retinal induces a change in the molecular configuration of its hydrocarbon chain—a process known as photoisomerization. After photoisomerization, opsin becomes chemically active and is able to initiate a series of biochemical events in the cones and rods that ultimately lead to a change in the number of glutamate molecules released by the photoreceptor. Glutamate, an amino acid and neurotransmitter, acts as a messenger that conveys to other retinal cells information about light stimulation of photoreceptors. Following its activation by light, an opsin molecule releases its transformed retinal molecule. Free opsin—an opsin that has released its retinal molecule—is likely to be the molecule responsible for the retina’s reduced sensitivity to light.

Dark adaptation is required for the recovery of this sensitivity. It is accomplished through a restoration of the original biochemical configuration of visual pigments. This involves a recombination of free opsin with an untransformed retinal—which results in a regeneration of cone opsins and rhodopsin. The rate of delivery of retinal to the photoreceptors is the probable reason for the relatively slow rate of dark adaptation. Since this process evolved to adapt to the slow changes in illumination that occur during the transition from day to night, the rate of change in sensitivity is quite adequate to compensate for changes in natural lighting.

Many diseases that interfere with the complex molecular mechanism underlying dark adaptation lead to night blindness. In addition to vitamin A deficiency, which is the most common cause of night blindness in the nonindustrialized world, inherited eye diseases can cause this condition. Many of these diseases, such as retinitis pigmentosa, are caused by mutations in the genes that code for the many proteins that drive the elegant molecular machinery involved in light detection.

For further reading:

The First Steps in Seeing. Chapters 4, 6, 7 and 8. R. W. Rodieck. Sinauer Associates, 1998.

The eyes have it—the clues to your health, that is. Sure, you need to be on the lookout for common eye conditions like glaucoma, cataracts, and macular degeneration. But your eyes may also tell you when things are seriously off elsewhere.

“Nothing in your body is in a box,” says Deborah Herrmann, MD, assistant professor of clinical ophthalmology and attending physician at Scheie Eye Institute at University of Pennsylvania’s Perelman School of Medicine. “Your eyes are connected to your central nervous system and everything else. Something that’s affecting your body can be affecting your eyes as well.”

Whether you’re feeling weird eye symptoms or seeing them when you look in the mirror, pay attention. Your peepers could be sounding the alarm about one of these 6 serious conditions.

High cholesterol

medical art inc/

“Someone with high cholesterol can have transient vision loss that comes and goes, like a curtain or shade coming and going over their eye,” says Herrmann. This is a sign your carotid artery is plugged with plaque and struggling to get blood to your eye. You may also have eye pain, notice a grey ring around your cornea (called an arcus senilis), or have trouble adjusting to bright light. In some cases, yellowish cholesterol deposits called xanthelasma can show up on your eyelids or in the corners of your eye socket.

MORE: 12 Foods That Lower Cholesterol Naturally

Thyroid problems

panda vector/

Your thyroid is a butterfly-shaped organ in your neck, and it controls certain hormones that help regulate your growth and metabolism. If your thyroid isn’t functioning properly it can lead to a host of problems, which sometimes includes swollen eye muscles and congested eye sockets that cause your eyes to bulge out and look bigger than usual, says Herrmann. You might also have double vision.

Graves’ disease, an autoimmune disorder that affects your thyroid, can make your eyelids retract, which can also make your eyes look bigger than usual. If your eyelids retract enough that you can’t close your eye, you may develop dry eye, since your lids can’t keep moisture in. (In as little as 30 days, you can be a whole lot slimmer, way more energetic, and so much healthier just by following the simple, groundbreaking plan in The Thyroid Cure!)

Diabetes

helgamariah/

Regular eye exams are a good idea for anyone, but it’s a must if you have diabetes or are at high risk for the disease. “Diabetes can make the macula—the part of the retina that controls your central vision—swell or retain fluid or fluid,” says Herrmann. While you might not completely lose your vision, she says, you’d definitely notice a change for the worse. People with diabetes are also 40% more likely to get glaucoma and 60% more likely to get cataracts, and they should be on the lookout for diabetic retinopathy—a set of disorders that affect the light-sensitive part of your eye. Retinopathy can cause problems like blurry vision or even retinal detachment.

MORE: 10 Reasons Your Eyes Are Bloodshot

Stroke

corbac40/shutterstcok

Sudden loss of sight is startling—and for good reason. It could be a sign that you’re about to have a stroke, or that you’ve already had one. Normally, vision loss from a stroke happens in one eye only, but it can happen in both, causing blindness. Sometimes strokes damage the nerves that move your eyes, which can make you see double.

Strange as it sounds, it’s also possible to have a stroke in your eye only. This is called a retinal stroke, and it happens when blood vessels in your retina are clogged with plaque. You’re more likely to get a retinal stroke if you have high blood pressure or carotid artery disease. Any kind of stroke is serious and calls for immediate care, so call 911 if you suddenly go blind in one or both eyes

MORE: Eat This, Reduce Your Stroke Risk By 20%

Retinal migraines

evannovostro/

Temporary blind spots in your vision could mean you’re having a migraine of the eye. This isn’t the same as a headache-type migraine. Retinal migraines cause “blank spots” in your vision called scotomas. ” only last for a certain number of minutes, and you may or may not have pain,” says Herrmann. You may also see flashes of light, have blurry vision, or get a headache before or after your eye symptoms. If it happens repeatedly—especially if it only impacts one eye—see an eye doctor to get checked out.

MORE: 7 Ways To Prevent Dry Eye

Autoimmune disease

disease designua/

Got droopy eyelids? It could be a sign of an autoimmune disorder called myasthenia gravis, which can cause muscle weakness that makes it hard to open your eyes all the way. Meanwhile, lupus and certain types of arthritis can lead to uveitis, an infection in the layer of your eye called the uvea. And eyesight changes are sometimes a clue that you should get screened for multiple sclerosis. “If you develop decreasing vision in one eye over the course of a few days or weeks and you have pain in or around one eye—especially when you move it—it could be your first presenting sign of MS,” says Herrmann.

What Causes It?

A wide range of conditions — from sun exposure to diabetes — makes it hard to see at night:

Cataracts . Your eye’s lens is right behind the pupil. As you age, cells grow and die inside it. That builds up debris and leads to cataracts. They don’t hurt, but they do get worse and slowly cloud your lens. The first symptom is often worse night vision. Because cataracts distort the light that comes into your eyes, you may see halos around lights — again, mostly at night. Blurry vision is also common.

Lack of vitamin A. It’s found in carrots and leafy vegetables. It helps keep the retina — the back of your eye where images are focused — healthy. Most Americans get enough vitamin A in their diets, but if you have a health issue that makes it hard for you to absorb nutrients (Crohn’s disease, celiac disease, gastric bypass), you might have night vision problems.

Not enough zinc. Without it, vitamin A may not work as well as it should. The result: night blindness. Beef, poultry, beans, and nuts are rich sources. Most people in the U.S. get plenty of it from their food.

Retinitis pigmentosa. This rare genetic disorder affects young people, usually before age 30. A decline in night vision is often the earliest symptom. Some people lose all their sight. Others keep some vision.

Sunlight exposure. Prolonged exposure to sunlight is a major risk factor for cataract development, is a major cause for poor night vision. Always wear your sunglasses when you’re out in the sun to help prevent this.

LASIK surgery problems. Complications after LASIK surgery are uncommon. But a few people have night vision problems after it. Complaints include glare and halos around objects, both of which distort vision. You may have symptoms during the day, too. They become more noticeable and bothersome, though, at night. The characteristics of your eyes may make you more prone to night vision problems after LASIK. So ask your doctor to check to see if you’re at risk.

Diabetes . It makes you more likely to have night vision problems. Over years, high blood sugar damages the blood vessels and nerves in your eyes, which leads to a condition called retinopathy. If you have trouble seeing in low light, either indoors or outside, talk to your doctor.

About the author

Leave a Reply

Your email address will not be published. Required fields are marked *