New components and chemistry concerned inside the most recent generations on the lenses have produced considerable progress in addressing the 2 basic standards for selection :
More mature generations (and some current generations) retain a yellow or slightly jaundiced hue even when not uncovered to ultra violet light-weight (indoors for example). The most recent generation Transitions are extensively regarded to become the very best available and almost completely clear within the absence of extremely violet.
Most newer photochromatic lenses create a fast changeover from light-weight to dim as they're uncovered to extremely violet - the genuine check along with the differentiation may be the price at which they regress in the darkest tint to obvious. Once more Transitions lenses are widely regarded as greatest in class within this regard.
Transitions lenses certainly are a widely held trademark for any particular (most recent) generation of supplies and technologies which are mixed and sold below the "Transitions" brand. Other (but related) names usually are not the identical, and are typically regarded to be not as great, as they may be from more mature technology photochromatic technology.
Ultimately - don't anticipate your photochromatic lenses (regardless of which manufacturer or technologies) to create considerably of a distinction while driving, as the windscreen of a auto is made to absorb the majority of the UV ahead of it enters the cabin - therefore the lenses within your eyeglasses have nothing to respond with. In case you need or would really like tinted lenses while driving, you might be better off receiving two pairs on the same frame with prescription very clear and prescription tinted lenses.