Crocs: no one said they're pretty, but everyone who wears these shoes like a badge of honor, praise their comfort. With more than 300 million pairs sold in 90 countries, according to Crocs, this comfort-touting footwear has taken the world's feet by storm. 
Unfortunately, not everyone is singing their praise, especially feet doctors. Despite the numerous praises for the ability to wear these shoes anywhere (from the park to the beach, if Amazon reviews are to be believed), several podiatrists issued a caution that these shoes are not that great for all-day wear, according to the Huffington Post. 

Dr. Megan Leahy, a podiatrist based in Chicago admitted that the shoes offer some arch support, but the lacked support elsewhere. "These shoes do not adequately secure the heel. When the heel is unstable, toes tend to grip which can lead to tendinitis, worsening of toe deformities, nail problems, corns and calluses," she told the Huffington Post. 

Leahy also noted that the same concerns apply to all backless shoes (including your favorite pair of flip-flops!) Croc now offers several different styles including loafers and sandal. 

Doctor Alex Kor, President of the American Academy of Podiatric Sports Medicine told the Huffington Post that the shoe lacks support between the heel and toe which can cause foot pain. While Kor did say that patients with a very high arch could benefit from wearing this type of shoe, he doesn't recommend it for all day wear. 

WebMD says this style of shoe can be particularly helpful for people with diabetes, as it helps get more circulation to the feet, and many other happy clients say they enjoy that the shoe is so lightweight and airy. 

Crocs aren't the only shoes making the naughty (or sorta-naughty list), WebMD lists ultra-high heels, ballet flats, flip flops and platform shoes among their list of worst shoes for your feet. In short: enjoy your favorite shoe, but keep a pair of tennis shoes on hand for extra long days.