A slit lamp isone of the devicesthat your healthcare provider may use for checking the health of your eyes. Getting regular eye examinations can help identify serious eye problems at an early stage when you might not have any symptoms and your vision isn’t affected.
When diagnosed early, eye diseases are usually more treatable.A slit lamp exam can be used to help in diagnosing conditions such asglaucoma,cataracts,macular degeneration,a detached retina, and more.
What Is a Slit Lamp?
A slit lamp is a microscope with a bright light that can be focused into a thin beam. It allows your eye practitioner to take a close look at the structures at the front and inside of your eye.
A slit-lamp examination is a non-invasive test, and it is not harmful. A slit lamp can only be used to observe your eyes—it is not used for a therapeutic procedure.
Verywell / Theresa Chiechi
What to Expect During the Exam
You do not need any specific preparation before having a slit lamp examination. However, right before the test, your eye care provider may place drops in your eyes to dilate (widen) yourpupils.
Your eye practitioner will ask you to sit in a chair and place your head on a piece of equipment that will keep your head steady. Your chin will rest on a chin rest, and your forehead against a forehead strap. This is not uncomfortable and it helps keep your head positioned properly for the exam.
With the slit lamp, your healthcare provider can see the following structures of your eye:
Dilating drops might be placed in your eye so your healthcare provider can see the structures in the back of your eye, including the retina and optic nerve. Dilating your pupil allows more light into your eye, which is helpful for identifying problems like glaucoma or age-related macular degeneration.
After the dilation drops are added, it takes about 15 to 20 minutes for them to work. Once they are working, your eye practitioner will examine your eye with the slit lamp again, using a different lens to look at the back of the eye.
The examination is not painful, but you may find it uncomfortable when the eye drops are added to your eye.
Side EffectsIn most cases, dilating drops don’t cause adverse effects. However, the dilating drops can temporarily make your vision blurry and your eyes sensitive to light. This will wear off after a few hours.You should arrange for someone to drive you home because it isn’t safe to drive with blurry vision.Wearing sunglasses will protect your eyes from sunlight until the sensitivity wears off.In very rare cases, symptoms like nausea, vomiting, eye pain, or dizziness might occur when dilating drops are used.If this happens, return to your eye practitioner right away as it could be a sign of increased fluid pressure in the eye, which is an emergency.
Side Effects
In most cases, dilating drops don’t cause adverse effects. However, the dilating drops can temporarily make your vision blurry and your eyes sensitive to light. This will wear off after a few hours.You should arrange for someone to drive you home because it isn’t safe to drive with blurry vision.Wearing sunglasses will protect your eyes from sunlight until the sensitivity wears off.In very rare cases, symptoms like nausea, vomiting, eye pain, or dizziness might occur when dilating drops are used.If this happens, return to your eye practitioner right away as it could be a sign of increased fluid pressure in the eye, which is an emergency.
In most cases, dilating drops don’t cause adverse effects. However, the dilating drops can temporarily make your vision blurry and your eyes sensitive to light. This will wear off after a few hours.
In very rare cases, symptoms like nausea, vomiting, eye pain, or dizziness might occur when dilating drops are used.If this happens, return to your eye practitioner right away as it could be a sign of increased fluid pressure in the eye, which is an emergency.
What Your Results Mean
After your slit lamp exam, your healthcare provider might tell you that your eyes appear healthy and no diseases have been detected.
The exam can also detect a problem with your eye or eyes. The slit lamp can help your practitioner diagnose several issues, including:
This is not an exhaustive list of eye conditions. Other diseases of the eye can be diagnosed during a slit lamp exam.
A Word From Verywell
Most eye problems can be detected early before they cause symptoms or problems with your vision. However, the Centers for Disease Control and Prevention estimate that 93 million adults in the United States are at high risk for severe vision loss. Still, only half visited an eye practitioner in the past twelve months.
An eye examination is safe, painless, and only takes about an hour of your time. It is beneficial to be proactive and have regular eye examinations to help keep your eyes in good health.
What Is an Eye Exam?
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Eye Institute.Get a dilated eye exam.Dartt D, Besharse J, Dana R.Imaging of the Cornea.Encyclopedia of the Eye.Amsterdam [Netherlands]: Elsevier/Academic Press; 2010:263-268.American Academy of Ophthalmology.What is a slit lamp?MedlinePlus.Slit-lamp exam.Centers for Disease Control and Prevention.Fast facts: vision loss.
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Eye Institute.Get a dilated eye exam.Dartt D, Besharse J, Dana R.Imaging of the Cornea.Encyclopedia of the Eye.Amsterdam [Netherlands]: Elsevier/Academic Press; 2010:263-268.American Academy of Ophthalmology.What is a slit lamp?MedlinePlus.Slit-lamp exam.Centers for Disease Control and Prevention.Fast facts: vision loss.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Eye Institute.Get a dilated eye exam.Dartt D, Besharse J, Dana R.Imaging of the Cornea.Encyclopedia of the Eye.Amsterdam [Netherlands]: Elsevier/Academic Press; 2010:263-268.American Academy of Ophthalmology.What is a slit lamp?MedlinePlus.Slit-lamp exam.Centers for Disease Control and Prevention.Fast facts: vision loss.
National Eye Institute.Get a dilated eye exam.
Dartt D, Besharse J, Dana R.Imaging of the Cornea.Encyclopedia of the Eye.Amsterdam [Netherlands]: Elsevier/Academic Press; 2010:263-268.
American Academy of Ophthalmology.What is a slit lamp?
MedlinePlus.Slit-lamp exam.
Centers for Disease Control and Prevention.Fast facts: vision loss.
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