Ranelagh Medical Centre

22-26 Sandford Rd. Ranelagh, D6

Vista Primary CAre Centre

Ballymore Eustace Road,
Naas, Co. Kildare

Urgent Eye Care Clinic

Lines Open Mon-Fri
Dublin 01 4986 920
Naas 045 881 000

Flashing lights and floaters

Flashes of light or black floaters that look like spiders or tadpoles and move around as you move your eye are quite commonly seen by people with normal eyes.


Tiny spots, lines, flashes or shapes in your vision are known as flashes and floaters. Lots of people experience them and they usually aren’t cause for alarm.

Flashes and floaters

What are floaters

Often, people who have healthy eyes see floaters. They appear as spots, lines or cobweb effects, usually when you look at a plain surface such as a white wall, screen or a clear blue sky. They are usually caused by cells clumping together in the clear jelly in the main part of your eye and casting shadows on your retina – the light- sensitive layer of the eye. The sudden appearance of new floaters is different and may be caused by the jelly shrinking and can sometimes mean there is a tear in the retina.

What are flashes

Sometimes the jelly inside your eye shrinks a little and tugs on the retina (the light-sensitive layer) at the back of your eye. This can
cause flashes of light at the edge of your vision.


Flashes and floaters happen because of changes in the vitreous, the clear, jelly- like substance that fills the inside of your eyeball. The vitreous jelly shrinks as you get older, and slowly pulls away from the inside surface of the eye. This shrinking and separation or detachment of the vitreous from the retina is a common phenomenon, particularly in people over 50 years of age, and causes no retinal damage in nine out of 10 patients. It is known as a posterior vitreous detachment.

When should I be concerned?

If you suddenly notice a shower of new floaters, or floaters along with flashes or a dark shadow or a ‘curtain’ in your vision, you should take urgent action. These symptoms can mean that the retina is tearing. The Vista Eye Clinic in Naas and Ranelagh has an Urgent Eyecare service. Patients with symptoms of flashes and floaters should contact our clinic (hyperlink to contact us) to arrange an urgent appointment. Where possible we will see patients on the same day.


Flashes and floaters need to be checked by an eye specialist. They rarely lead to any serious complications, and in many cases, the flashes disappear with time and the floaters get less noticeable as your brain adjusts to the jelly change.

However, if the retina has a tear or has detached then you will require laser treatment or eye surgery to repair the retina.

If your flashes or floaters become much worse, you should consult your GP, your optometrist (optician) or contact our specialist Urgent eyecare services in Naas or Ranelagh to exclude any serious problems. If you see a black shadow or curtain effect or you suddenly lose vision, you should go to your nearest hospital eye casualty department without delay.


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Vista Eye Clinic,
Ranelagh Medical Centre,
22-26 Sandford Road,
Dublin 6, 
D06 A365

01 4986920

Naas, Co. Kildare

Vista Eye Clinic
Vista Primary Care Centre,
Ballymore Eustace Road,
Co. Kildare,
W91 XW83

045 881000

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