Q: What exactly is astigmatism?
A: Usually it is related to the shape factor of the front surface of the eye called the cornea. Instead of being shaped spherically like a ball bearing or a marble, it is shaped like a football, being more curved in one direction than the other. This brings light to focus at more than 1 point. The root word stigma means point and the prefix A means without a point focus in the eye.
Q: I have heard about blue light being a concern as well. Can you talk a little bit about this and what it means for protecting your eyes?
A: Recently, the optical community has found that blue light can also cause long term damage to the eye. It has been found that overexposure to blue light over time can lead to macular degeneration. To help protect our eyes from these rays, a new coating has been found to block out this blue light. Anti-reflective or anti-glare coating could be a term that is familiar to you. Labs have found a way for these features to block the blue rays coming from our handheld devices, computers and fluorescent bulbs. This coating has several benefits and protecting our eyes from these harmful rays is one of them.
Q: Does reading my smart phone or tablet in the dark damage my eyes?
A: Reading from a tablet or smart phone in the dark is okay for your eyes, as long as this is not for a long period of time. There is good lighting from these devices, with good contrast. There is, however, blue light emitted from these devices. Blue light is a short wavelength light, with high energy that may cause damage to the structures of the eye if exposed for a long period of time. As well, studies have shown this blue light can disrupt melatonin production which is required for a healthy sleep cycle. Doctors of Optometry recommend limiting screen use during the last hour before bedtime.