Eyes and driving

Eyestrain, glare and problems with vision at night, dangers to be aware of when travelling by road during the holidays.

In summer, especially in August, the amount and duration of car journeys we make increases and vision plays a key role. Through our eyes, we receive 90% of the information we need to drive so factors such as glare can seriously compromise our road safety.

Protection from the sun

As explained by Dr. Daniel Elies, a cornea, cataract and refractive surgery specialist at IMO, “solar radiation is a major risk factor, not only for our eye health, as it causes the onset of diseases such as pterygium and is associated with an increased incidence of disorders such as cataracts and AMD, but also for driving, as it can reduce visibility and increase the likelihood of an accident”.

To prevent this, “it is essential to use sunglasses and to always have them to hand in the car. It is advisable for them to have polarised lenses to eliminate glare and selective filters to block infrared and ultraviolet radiation”, explains Carol Camino, head of IMO’s Low Vision Department. As the optometrist adds, “another type of filter suitable for combating photophobia is the photochromic lens for driving which changes colour depending on how light strikes it”.

Vision at night

Another very common source of glare at night are vehicle headlights and streetlights, which, according to IMO optometrist, can be alleviated by using “glasses with an anti-reflective coating”.

For night driving, she also recommends “special glass that incorporates a small negative lens because in the dark a fogging phenomenon can occur: the pupil dilates, rays enter more unfocused and we see worse”.


Loss of visual acuity and contrast sensitivity, as well as decreased visual field and depth perception are other factors that increase the risk of night driving and add to the fatigue caused by many hours behind the wheel.

“Eyestrain often leads to sleepiness while driving, especially among people with mild refractive errors who do not use optical correction or those who wear glasses with an incorrect optical power, due to the visual effort involved” explains Carol Camino.

Eyesight MOT

Just as it is important for your vehicle to undergo an annual MOT or for its tyres and brakes to be checked before going on long journeys, it is also advisable to undergo a regular “eyesight MOT” with annual or biannual check-ups instead of just waiting for your driving licence to expire. This facilitates the early detection of eye diseases that can significantly affect road safety, such as glaucoma, which gradually reduces peripheral vision; catarats, which cause blurred vision; and AMD, which causes straight lines to look crooked and leads to loss of central vision.

Symptoms on the road

At the same time, as highlighted by Carol Camino, “certain symptoms on the road can alert us to the need to go and visit the ophthalmologist”. In this regard, Dr Elies warns that “if your eyes experience excessive discomfort or difficulty adapting to the light after leaving the darkness of a tunnel, it could be a sign of retinal diseases such as AMD or diabetic retinopathy. Conversely, high photophobia could be indicative of pathologies of the anterior chamber, such as cataracts, keratoconus, certain corneal dystrophies and dry eye”.

Our experts’ advice is to protect your eyes from the sun and the headlights of vehicles at night, as well as undergoing an “eyesight MOT” before going on long car journeys.