What are eye floaters?
Eye floaters (known as floaters) are tiny specks that can be seen in your field of vision – especially when you look at a light-coloured area (such as a blue sky or white wall).
They are created when tiny clumps form in the clear, jelly-like substance (the vitreous humour) inside the eyeball. Eye floaters are suspended in this ‘jelly’, so they move when your eyeball moves. If you try to look directly at them, the floaters may seem to disappear.
Floaters can come in different sizes and shapes. Some floaters look like small dots, while others appear like threads or little hairy clumps. It is common for individuals to describe them as looking like cobwebs or the shadow of an insect.
In most cases, floaters are normal and harmless. However, a sudden increase in their number may indicate damage to particular internal structures of the eye. This requires immediate eye health professional attention.
Eye floaters in vitreous humour
The eye contains vitreous humour, which is a clear, jelly-like substance that helps maintain the shape of the eyeball. Vitreous humour acts as a shock absorber when the eye is pushed out of shape.
The vitreous is more than 98 per cent water, but is 2 to 4 times more viscous.
Floaters are suspended in the vitreous humour, which means they move around. Floaters in your peripheral vision tend to go unnoticed, but sometimes particles can cross in front of the central vision.
Symptoms of eye floaters
Some characteristics of floaters can include:
- They can be different shapes – such as tiny spots, flecks, clear little bubbles, threads or webs.
- They are particularly visible when looking at a light-coloured area (such as a blue sky).
- They move as the eyes move, often with a slight lag.
- Large floaters can present as diminished areas of vision, but this is very rare.
Treatment for eye floaters
If a floater troubles you, try looking up and down, and from side to side, to swish the vitreous humour and move the floater out of the way.
However, this does not always work. While some people find floaters troublesome, they are typically harmless and surgery is not needed.
Floaters increase with age
Eye floaters tend to increase with age due to changes that occur in the retina. The retina is a thin film that lines the inside of the eye. It is made up of light-sensitive cells known as rods and cones. Rods and cones detect shape, colour and pattern, and pass the information to nerve fibres.
Nerve fibres collect in a bundle at the back of the retina, forming the optic nerve. Visual information is relayed from the retina to the brain via this optic nerve.
The vitreous humour pulls slightly away from the retina and degenerates with advancing years. This separation of vitreous humour from the retina can cause small shreds of jelly to break off and form more floaters.
At first, this can be irritating. Eventually, the brain can become accustomed to the floaters and may decide not to ‘inform’ you of their presence.
Damage and tears to the retina
In some people, the age-related detachment of the vitreous humour from the surface of the retina may cause tears. Tiny droplets of blood may appear on the retina as a fresh crop of floaters.
Short-sighted people and those who have undergone surgery for cataracts are at increased risk of tears to the retina.
Untreated retinal tears can lead to retinal detachment. In this condition, the retina comes away from the back of the eyeball.
Permanent loss of vision can result if immediate treatment is not sought.
Flashing lights ('auras') and floaters
Sometimes, floaters can be associated with flashing lights or ‘auras’. This can be caused by events including:
- vitreous humour pulling at the retina, when moving or turning your eye quickly
- retinal detachment
- migraine – with or without associated headaches
- postural (or orthostatic) hypotension – getting up quickly from sitting or lying down resulting in dizziness and vision disturbance
- high blood pressure
- a traumatic blow to the eye.
Seek help for any sudden eye changes
Floaters are usually harmless but you should seek immediate attention from an eye health professional with the onset of new floaters, or if you experience a sudden increase in floaters (particularly if they occur as flashing lights (auras).
This is especially important if you are short-sighted.
Eye care professionals, such as optometrists and ophthalmologists, use specialised equipment to examine the vitreous humour and the retina to determine whether there has been any tearing or detachment of the retina.
Retinal detachment is treated with surgery.
