Cataract is a disease which affects mostly older people and progresses slowly. One of the major symptoms people develop is the need for more light for normal day to day activities like reading etc. Basically the amount of light that enters the eye progressively gets reduced due to increasing opaqueness of the lens. Our brain and eye adapts to that to a certain extent. Due to this adaptation many people after cataract surgery notice increased brightness around them and in some cases it may be uncomfortable. This is partly due to the fact that the eye is suddenly exposed to more light as soon as cataract is operated and brain has not yet adapted to that. This is turn gives a feeling of increased light sensitivity. However good news is that it is temporary phenomenon and it tends to settle down in the first few weeks after the surgery.
“Mr. Lal on his one week follow up complained that everything appears too bright and he often needs to use sun glasses even when he is inside the house especially if all the windows are open. In these situations once we make sure that recovery of the eye after the cataract surgery is otherwise normal we just reassure“.
Causes for increased light sensitivity after cataract surgery
- Slow adaptation of eye: Increased light entering the eye after cataract surgery is the foremost cause of increased light sensitivity after the cataract surgery. The new lens which is implanted inside the eye does not block the light the way cataract lens was doing prior to the surgery. However the brain adapts to this new state in a few weeks. In the interim period a good quality sun glass can be used as and when required.
- Corneal swelling: Second common reason for increased light sensitivity after cataract surgery is mild to moderate amounts of corneal swelling after cataract surgery. The causes for corneal swelling are many and in most cases it settles down within the first few weeks itself. Only if corneal swelling is severe and the swelling is not diminishing over the first few weeks that we need to get concerned. However due to modern advanced surgical options prolonged or irreversible corneal edema is very rare. If happens it may be due to some pre-existing corneal diseases like Fuchs endothelial dystrophy or severe surgical trauma in more advanced cataracts.
- Increased eye pressure– Very rarely eye pressure may increase after the cataract surgery. This is turn can increase light sensitivity. In such a situation extra medicines are given to control the eye pressure.
- Increased Inflammation (swelling inside the eye) – Increased inflammation inside the eye can also increase the light sensitivity. This often requires your eye doctor to increase the frequency of your post operative medication and to rule out any secondary cause for increased eye inflammation
- Dry Eye– Dry eye is one of the common causes where light sensitivity may persist beyond the first few weeks also. In some cases dry eye can cause formation of punctuate (tiny pin point) erosion’s on the corneal surface. Cornea being a very sensitive structure increases the sensitivity to the light. In these cases adding some lubricating eye drops and gels and warm compress may help.
- Dilated pupil– Pupil is the aperture which controls the amount of light entering the eye. So if pupil is large it allows more light to enter the eye. This can cause increased light sensitivity.
In most cases the common and normal cause of increases light sensitivity is just the fact that the opaque cataract lens is replaced with a new transparent lens during cataract surgery which allows more light to enter the eye. This is not a complication of cataract surgery. The light sensitivity settles down in a few weeks during the recovery period after cataract surgery as the brain adapts to the new normal level of light intensity.