Vision problems
Vision impairment; Impaired vision; Blurred vision
There are many types of eye problems and vision disturbances, such as:
- Halos
- Blurred vision (the loss of sharpness of vision and the inability to see fine details)
- Blind spots or scotomas (dark "holes" in the vision in which nothing can be seen)
Vision loss and blindness are the most severe vision problems.
People are very sensitive to other individuals' eye positions. By looking at another person's eye position, one can very effectively gauge where they are looking. People are also sensitive to eyes that are not looking in the same direction, which is referred to as crossed eyes (strabismus). Other more specific medical terms refer to eyes turned either outward or inward, or that are abnormally rotated. Any appearance of crossed eyes in young children should be immediately evaluated, as should recent onset of crossed eyes in an adult.
The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.
Visual acuity tests may be performed in many different ways. It is a quick way to detect vision problems and is frequently used in schools or for mass screening. Driver license bureaus often use a small device that can test the eyes both together and individually.
A slit-lamp, which is a specialized magnifying microscope, is used to examine the structures of the eye (including the cornea, iris, vitreous, and retina). The slit-lamp is used to examine, treat (with a laser), and photograph (with a camera) the eye.
Central and peripheral vision is tested by using visual field tests. Changes may indicate eye diseases, such as glaucoma or retinitis.
This photograph shows a cloudy white lens (cataract) as seen through the pupil. Cataracts are a leading cause of decreased vision in older adults, but children may have congenital cataracts. With surgery, the cataract can be removed, a new lens implanted, and the person can usually return home the same day.
A cataract is a cloudy or opaque area in the lens of the eye. Cataracts usually develop as a person gets older and may run in families. Other environmental factors such as smoking or exposure to toxic substances can also accelerate the development of a cataract. Cataracts can cause visual problems such as difficulty seeing at night, seeing halos around lights, and sensitivity to glare.
Considerations
Regular eye checkups from an ophthalmologist or optometrist are important. They should be done once a year if you are over age 65 years or older. Some experts recommend annual eye exams starting at an earlier age.
How long you go between exams is based on how long you can wait before detecting an eye problem that has no symptoms. Your provider will recommend earlier and more frequent exams if you have known eye problems or conditions that are known to cause eye problems. These include diabetes or high blood pressure.
These important steps can prevent eye and vision problems:
- Wear sunglasses to protect your eyes.
- Wear safety glasses when hammering, grinding, or using power tools.
- If you need glasses or contact lenses, keep the prescription up to date.
- Do not smoke.
- Limit how much alcohol you drink.
- Stay at a healthy weight.
- Keep your blood pressure and cholesterol under control.
- Keep your blood sugar under control if you have diabetes.
- Eat foods rich in antioxidants, like green leafy vegetables.
Causes
Vision changes and problems can be caused by many different conditions. Some include:
- Presbyopia -- Difficulty focusing on objects that are close. This problem often becomes noticeable in your early to mid-40s and is very common.
- Cataracts -- Cloudiness of the eye lens, causing poor nighttime vision, halos around lights, and sensitivity to glare. Cataracts are common in older people.
- Glaucoma -- Increased pressure in the eye, which is most often painless. Vision will be normal at first, but over time you can develop poor night vision, blind spots, and a loss of vision to either side. Some types of glaucoma can also happen suddenly, which is a medical emergency.
- Diabetic eye disease.
- Macular degeneration -- Loss of central vision, blurred vision (particularly while reading), distorted vision (straight lines will appear to be wavy), and colors that look faded. The most common cause of blindness in people over age 60 years.
- Eye infection, inflammation, or injury.
- Floaters -- Tiny particles drifting inside the eye, which may be a sign of retinal detachment.
- Night blindness.
- Retinal detachment -- Symptoms include floaters, sparks, or flashes of light in your vision, or a sensation of a shade or curtain hanging across part of your visual field.
- Optic neuritis -- Inflammation of the optic nerve from infection or multiple sclerosis. You may have pain when you move your eye or touch it through the eyelid.
- Stroke or TIA.
- Brain tumor.
- Bleeding into the eye.
- Temporal arteritis -- Inflammation of an artery in the brain that supplies blood to the optic nerve.
- Migraine headaches -- Spots of light, halos, or zigzag patterns that appear before the start of the headache.
Medicines may also affect vision.
Home Care
See your health care provider if you have any problems with your eyesight.
When to Contact a Medical Professional
Seek emergency care from a provider who is experienced in dealing with eye emergencies if:
- You experience partial or complete blindness in one or both eyes, even if it is only temporary.
- You experience double vision, even if it is temporary.
- You have a sensation of a shade being pulled over your eyes or a curtain being drawn from the side, above, or below.
- Blind spots, halos around lights, or areas of distorted vision appear suddenly.
- You have sudden blurred vision with eye pain, particularly if the eye is also red. A red, painful eye with blurred vision is a medical emergency.
Get a complete eye exam if you have:
- Trouble seeing objects on either side.
- Difficulty seeing at night or when reading.
- Gradual loss of the sharpness of your vision.
- Difficulty telling colors apart.
- Blurred vision when trying to view objects near or far.
- Diabetes or a family history of diabetes.
- Eye itching or discharge.
- Vision changes that seem related to medicine. (Do not stop or change a medicine without talking to your doctor.)
What to Expect at Your Office Visit
Your provider will check your vision, eye movements, pupils, the back of your eye (called the retina), and eye pressure. An overall medical evaluation will be done if needed.
It will be helpful to your provider if you can describe your symptoms accurately. Think about the following ahead of time:
- Has the problem affected your vision?
- Is there blurring, halos around lights, flashing lights, or blind spots?
- Do colors seem faded?
- Do you have pain?
- Are you sensitive to light?
- Do you have tearing or discharge?
- Do you have dizziness, or does it seem like the room is spinning?
- Do you have double vision?
- Is the problem in one or both eyes?
- When did this begin? Did it occur suddenly or gradually?
- Is it constant or does it come and go?
- How often does it occur? How long does it last?
- When does it occur? Evening? Morning?
- Is there anything that makes it better? Worse?
The provider will also ask you about any eye problems you have had in the past:
- Has this ever happened before?
- Have you been given eye medicines?
- Have you had eye surgery or injuries?
- Have you recently traveled out of the country?
- Are there new things you could be allergic to, such as soaps, sprays, lotions, creams, cosmetics, laundry products, curtains, sheets, carpets, paint, or pets?
The provider will also ask about your general health and family history:
- Do you have any known allergies?
- When did you last have a general checkup?
- Are you taking any medicines?
- Have you been diagnosed with any medical conditions, such as diabetes or high blood pressure?
- What kinds of eye problems do your family members have?
The following tests may be performed:
- Dilated eye exam
- Slit-lamp examination
- Refraction (test for glasses)
- Tonometry (eye pressure test)
Treatments depend on the cause. Surgery may be needed for some conditions.
References
Chou R, Dana T, Bougatsos C, Grusing S, Blazina I. Screening for impaired visual acuity in older adults: updated evidence report and systematic review for the US Preventive Services Task Force. JAMA. 2016;315(9):915-933. PMID: 26934261
Cioffi GA, Liebmann JM. Diseases of the visual system. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 395.
Chaves-Gnecco D, Feldman HM. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire SC, Nowalk AJ, Garrison J, eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 3.
Piyasena P, Olvera-Herrera VO, Chan VF, et al. Vision impairment and traffic safety outcomes in low-income and middle-income countries: a systematic review and meta-analysis. Lancet Glob Health. 2021;9(10):e1411-e1422. PMID: 34411516
Thurtell MJ, Prasad S, Tomsak RL. Neuro-ophthalmology: afferent visual system . In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 16.
US Preventive Services Task Force; Grossman DC, Curry SJ, et al. Vision screening in children aged 6 months to 5 years: US Preventive Services Task Force Recommendation Statement. JAMA. 2017;318(9):836-844. PMID: 28873168
Version Info
Last reviewed on: 8/22/2022
Reviewed by: Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
