Novartis has estimated Alcon's value at around 25 billion Swiss francs (19.06 billion pounds), while some analysts predict an initial market capitalisation of 21 billion francs ($21 billion) to 23 billion, implying shares worth from 43 to 47 francs.
By contrast Baer's value has tumbled by a third in a year to 9.3 billion francs. It will instead be included in the SMIM index, replacing Aryzta, SIX Swiss Exchange said after Tuesday's market close.
Dominated by Nestle, Novartis and Roche, the SMI is Switzerland's most important index. Membership is based on market capitalisation, adjusted for the free float of readily tradable shares in its constituents.
Alcon is being spun off in a one-for-five share deal announced by Novartis last June as it focuses on new drugs rather than the surgical devices and contact lenses Alcon makes.
Joining the SMI may boost demand from funds focusing on the top Swiss companies. Yet Alcon's inclusion means healthcare and medical technology will weigh even more heavily on the SMI.
Novartis's weighting had been capped 18 percent, but with Alcon the two will account for up to 21.5 percent of the SMI, Zuercher Kantonalbank analysts estimated on Wednesday.
Novartis's biggest owners - BlackRock, the Sandoz family, Capital Research Global Investors and Vanguard Group - will have similar holdings in Alcon, between 2.5 percent and 4.5 percent.
"We anticipate incremental buying of Alcon shares by some funds seeking to build a full-size position, offset by others not wanting to own a non-pharma eyecare company," Jefferies analyst Peter Welford said.
Novartis bought Alcon's eye surgery and contact lens portfolio in stages through 2010 for $52 billion from Nestle, only to see it lose ground to competitors as sales and profitability slipped.
In surgical equipment, Alcon competes against Johnson & Johnson, Germany's Zeiss and Bausch in a $9 billion per year market. Rivals in vision care, worth $14 billion annually, include J&J, Cooper and Bausch.
In 2016, a new Alcon head, Mike Ball from Hospira, redoubled research and marketing spending to resurrect revenue, before Novartis chief Vas Narasimhan decided to shed the division.
The last comparable-sized Swiss listing was in 2010, when oil driller Transocean floated on the same day its Deepwater Horizon rig exploded in the Gulf of Mexico.
(Editing by David Holmes)
By John Miller and Paul Arnold