When you stand up suddenly, for a few moments your blood will lag behind in your legs, and what you'll notice are the effects of not having enough blood getting to your brain. You'll feel like you might faint, what some people call “dizzy.” Many people will also notice changes in their vision when this happens.
What is the cause? The most common cause of temporary vision loss is reduced blood flow to your eye. You have a large blood vessel on each side of your neck that brings blood from your heart to your eyes and brain. Fatty deposits called plaque may build up in blood vessels and make them more narrow.
On the other hand, if you frequently feel light-headed, experience dimming of your vision, ringing in your ears, weakness of your legs, or pain of the neck and shoulders when standing up, and your symptoms go away once you sit down, you may have orthostatic hypotension.
Prescyncope is when you feel as if you're about to pass out, but you don't actually faint. It's sometimes referred to as near syncope. You may also feel lightheaded, sweaty, nauseous, warm, and weak, or have a fast heartbeat or blurry vision.
Most of the time, feeling dizzy when you stand up is just a temporary nuisance, caused by something that's fairly easy to correct. However, it can lead to a dangerous fall if severe and can also be a sign of an underlying health condition so it's important to tell your doctor if it's happening frequently.
Increased intracranial pressure (the pressure of the fluid around the brain) can cause momentary lapses of vision especially when moving, such as standing from a sitting position. Sometimes even eye movements are enough to induce a temporary loss of vision.
This is called orthostatic hypotension, and it occurs when blood pressure drops suddenly after you stand or change posture. Orthostatic hypotension is part of a category of temporary loss of vision called transient obscurations of vision (TOV), which only last for several seconds.
This is a symptom of a variety of conditions, including amblyopia, optic neuritis, retinal detachment, macular degeneration, glaucoma, cataracts, or brain tumor. If you note dimness of vision, see an ophthalmologist to have the problem diagnosed and treated.
Fainting is a temporary loss of consciousness. If you're about to faint, you'll feel dizzy, lightheaded, or nauseous. Your field of vision may "white out" or "black out." Your skin may be cold and clammy. You lose muscle control at the same time, and may fall down.
When we are severely stressed and anxious, high levels of adrenaline in the body can cause pressure on the eyes, resulting in blurred vision. People with long-term anxiety can suffer from eye strain throughout the day on a regular basis.
The sudden appearance of spots within your field of vision could also be a symptom of a more serious condition. Sudden blindness may only last a short time such as a few seconds or hours; however, it could potentially be permanent, especially if not treated quickly.
Migraines are the most common causes of temporary vision loss. Migraines may cause blind spots or you may feel like you are seeing flashing lights. Migraines cause Sudden Blindness in both eyes. Giant cell arteritis is another cause of temporary blindness in one eye.
Symptoms of orthostatic hypotension
The drop in blood pressure reduces the flow of oxygenated blood to the brain. Symptoms may include: Blurry vision.
“Transient visual obscurations, also known as TVOs, last seconds,” says Cestari. “They can appear as flashes of white light and cause a loss of vision. TVOs are caused by swelling of the optic nerve and can happen when you change position, say, standing up quickly.”
When a blood vessel in your retina tightens, it causes a vasospasm. This cuts down on blood flow, which can bring on temporary vision loss in one eye. Various conditions can lead to a vasospasm. These include a retinal migraine, atherosclerosis, and high blood pressure.
Common causes of sudden vision loss include eye trauma, blockage of blood flow to or from the retina (retinal artery occlusion or retinal vein occlusion), and pulling of the retina away from its usual position at the back of the eye (retinal detachment).
If mental stress causes vision loss and vision loss leads to stress, this results in a downward spiral: mental stress impairs vascular function in the ocular structures leading to vision loss; this causes emotional worry and stress, which, in turn, aggravates vision loss and so on.
It is easy to take clear vision for granted, but even subtle changes in the structure or functioning of the eyes can disrupt our sight. Humans are blind for about 40 minutes per day because of Saccadic masking—the body's way of reducing motion blur as objects and eyes move.
Floaters, Gray Shadows in Your Vision, and Flashing Lights
While floaters aren't apparent symptoms that signal you're losing vision, if there are a lot of them, accompanied by a sudden onset of a gray curtain in your vision field with flashing lights, you should see your doctor right away.
Eye and vision anxiety symptoms common descriptions include: Experiencing visual irregularities, such as seeing stars, shimmers, blurs, halos, shadows, “ghosted images,” “heat wave-like images,” fogginess, flashes, and double-vision. See things out of the corner of your eye that aren't there.
Depression and Vision
Clinically depressed individuals or people going through periods of intense stress are more likely to experience the following vision problems: Blurred vision: Individuals may experience a lack of sharpness in their vision, preventing them from seeing fine details clearly.
Reasons why your eyes may go blurry at night can include: You are tired so your visual system is fatigued. You have a refractive error such as long-sightedness or astigmatism. During the day, you may be able to compensate for these, but when your eyes are tired, your vision can go blurry.