Having your eyes dilated in the Eye Doctor's clinic can be a time consuming affair leaving you blurry eyed for the rest of the day. Is it absolutely essential?

A standard practice among all eye doctors is applying drops in the eye to dilate the pupil and examine the eye. Dilatation can take from 20 to sometimes 45 minutes of waiting with your eyes closed and leave you blurry eyed for about 4-5 hours afterwards. Driving or reading after dilatation becomes difficult and is best avoided. A very common question most patients have is whether eye dilatation is absolutely necessary and that too at every visit.

Driving at night with the eyes dilated can be a challenge, best avoided

Imagine looking through the keyhole of a door to a room to look at the details inside. You might want to look at the colour of the walls, the details on the curtains or the cracks in the ceiling. The keyhole gives you an idea of what is inside but it does not give you any details. Worse, it gives you no clue to anything insidious hiding inside. What would you do to get a better look at the room? Open the door, of course. Dilatation of the pupils of the eye is pretty much the same. It opens the door for the eye doctor to examine the insides of the eye completely.

Dilatation of the pupil helps your eye doctor examine the interior of the eye in detail

The drops used for dilatation are very quick acting and quickly reversible. They start acting the minute they are instilled and complete dilatation can be achieved in 30 minutes for most people. Some eyes take a longer time dilating - usually Diabetics, very elderly people and abnormal pupils which are stuck, take time.

The dilating compound called Tropicamide causes a momentary stinging which passes off in an instance. A repeat instillation of the drops may be required after 15 minutes.

After dilatation, the eye doctor can examine in detail the entire extent of the retina (the sensory inside layer - the film of the eye), the crystalline lens (the focussing mechanism of the eye which develops cataract) and the optic nerve head (the starting point of the optic nerve which transmits images to the brain). Various diseases lurking silently in the back of the eye can be picked up only after dilatation of the eye. For eg.,

  • Diabetic Retinopathy
  • Peripheral Retinal Holes leading to Retinal Detachment
  • Cataract Diagnosis and Staging
Early Diabetic Retinopathy is treatable and even reversible. Late stages may result in permanent vision loss

Is there any risk with dilatation?

Eyes with the risk of developing congestive glaucoma should not be dilated. Your eye doctor usually examines your eye to ascertain the risk of developing this condition before dilatation. Rarely one can develop an allergic reaction to the drugs used for dilatation. This results in redness and watering of the eyes with puffiness of the eyelids. Patients known to have such a drug allergy can opt for an alternate eye drop.

Is dilatation necessary on every visit?

If a problem is identified on dilated eye exam your eye doctor might want to examine you periodically for noting the progress of the problem. Diabetics need periodic dilatation to screen them for any changes which might suggest retinopathy. 

So, the next time you are waiting for your eye examination, remember that it is time well spent. Do bring your headphones and listen to some music and bring a friend to drive you home after the dilatation.