This is a review of the Zeal Optics Eclipse Polarized Automatic and the Smith Optics I/OX Photocromic goggles. Photocromic lens change darker and lighter depending on the light conditions.
FIT: The fit is a bit different with the Smith slightly larger top to bottom plus the nose part fits slightly different. They both work for me but I prefer the Zeal. Other reviewers sometimes found the Zeal to not fit well on the nose but it works for me. Each to their own.
VENTILATION: They both prevent fogging well. The Smith lets in more airflow which, on cold days can be a bit chilly but not an issue.
PERIPHERAL VISION: Both are excellent at showing the peripheral view on you left and right sides.
PHOTOCROMICS: They both change equally fast when going in and out of trees.
VLT RANGE, (Visual Light Transmission)- They are different with the Smith's getting lighter but not as dark on the extremes of the lens VLT changes. For very cloudly days the Smith works better as you can see well in the open areas with flat light and in the trees when cloudy, but they have a bit of glare on sunny days in the open. I don't think they are polarized, which increases glare on snow with bright sun. The Zeal's work great in sunny and partly sunny days, being a little darker then the Smith's. They are polarized so you can see clearly without glare. In the trees on sunny and partly sunny days it is excellent, but on very cloudy days the visibility isn't as good as the Smith's in the trees. In the open even on cloudy days the Zeal's are good.
CONCLUSION: Go with the best fit against your face and goggles. If equal, I prefer the Zeal's for the skiing that I do in Colorado.