This is the 3rd installment in our series on improving eyesight while driving. Last month we covered sources of glare outside of the eye; now we are going to cover the ocular anatomy & how glare can be caused by the eye itself.
The goal for you and your eye doctor is to maximize the amount of clearly focused light reaching the back of the eye, the retina. The more light our eyes receive and the clearer the images, the faster our brains can process the input to react.
The Eye Itself: Maximizing our Eyesight & Reducing Glare While Driving
1. The Cornea
The cornea is the clear “dome” over the colored part of the eye. The cornea is covered by our tear layer, and the tears actually function as a part of the optical system of the eye. Having dry eyes (reduced or poor tear quality) causes the quality of our eyesight to suffer. As we mature, our eyes typically produce fewer natural tears, making this problem worse. The heating & air conditioning vents can also severely dry out the eyes while driving if they are pointed directly at the face. A dry ocular surface will increase glare and create an irregular optical surface for light to pass through into the eye. Do not dismiss dry eyes if you are a sufferer. Talk to you doctor about over the counter and prescription treatments available.
2. Pupil Size
The pupil is not actually a structure of the eye, but rather it’s the black hole which allows light into the eyes. Our pupils naturally become smaller as we mature. It is common for our pupils to be half the diameter at age 70 of what they were at age 20. This reduction in pupil size decreases the amount of light entering the eye, requiring brighter light conditions to see well as we mature. While it seems contradictory to wear sunglasses when your pupils are smaller and require more light, wearing polarized sunglasses is important as we mature. In bright light, our pupils naturally constrict further. A small pupil will become even smaller when it’s bright. By wearing sunglasses, the darkening effect of the tinted lens prevents prompts the pupil to remain larger, allowing more light to enter the eye.
3. Physiological Lens
The clear lens we are born with in each eye develops a yellowing or haziness over time, which is a cataract. Cataracts scatter light and increase glare. While keeping your eyeglass prescription up to date and using polarized sunglasses, these things can’t fully overcome all the glare when a cataract is present.
4. The Retina
The retina is the lining on the inside of the eye where light is ultimately focused. While dozens of conditions can affect the retina and reduce one’s ability to see well when driving, perhaps the most well-known condition is Age-Related Macular Degeneration (AMD.) Early signs of AMD are often first detected during an eye examination, prior to the patient being aware of its presence. Cigarette smoking is linked to AMD, as is Ultraviolet light exposure. Seeing your eye care provider regularly helps detect early signs of condition and multiple avenues to help mitigate it’s effects will be discussed by the doctor.
5. The Brain
Eyesight actually takes place in our brains- the eyes just help deliver the images there! Decrease other distractions while driving so your brain to minimize tasks at hand. Avoid talking on your cell phone, programming a navigation system, or other audible or visual distractions.
Best Tips for Maximizing your Eyesight while Driving
- Annual examinations with your eye doctor. Report any symptoms of ocular dryness to your doctor. Common symptoms of dry eyes include a sandy, gritty feeling, burning, and excessive tearing. Don’t cut corners on inferior optical products, you may otherwise pay with visual discomfort and reduced acuity.
- Use a non-glare eyeglass lens treatment (Crizal is one brand) to reduce glare, reflections, and improve light transmittance into the eyes.
- Use sunglasses when driving, either prescription or non-prescription. Polarized lenses are far superior to non-polarized lenses for driving conditions. This helps control pupil size and aids in the illumination of the retina.
- Limit other visual and auditory distractions not critical to driving such as cell phones, engaging in arguments, and “rubber-necking” at accident scenes.
This article was Part 3 in our series “Vision and Driving.” If you would like to view Part 1 or Part 2, please click on the links below:
Be sure to have your annual eye exam to maximize your eyesight while driving. If you would like to see how our Crizal non-glare lens can improve your vision and driving experience, set up an appointment today to come see us!